Yes, actually... There is! But before anything else, I'm going to show why there is a seeming contradiction between Luke 23:43 and John 20:17 in the first place. In Luke 23:43, Jesus clearly tells the thief that he(the thief) will be with him(Jesus) in paradise today, and by "today" we automatically assume Jesus is talking about the "current 24-hour period of rotation on the Earth's axis." And in John 20:17, Jesus unequivocally states that HE had not been with the Father yet. So, if the thief had not been with Jesus in paradise that very 24 hours(assuming he was operating under such a definition of "day"), then Jesus would have lied. And the scriptures make it quite clear that God cannot lie(whether or not you believe Jesus is God shouldn't matter, as Jesus is the exact representation of God[see Hebrews 1:3 and Colossians 1:15]. So, it being impossible for God to lie directly corresponds to it being impossible for Jesus to lie); see Numbers 23:19, Hebrews 6:18, and Titus 1:2. Hence, lest we admit that Jesus lied, we have a (seeming) contradiction.
But I know what you are thinking; why do we have to say that Paradise is in heaven? Why can't we just say it's somewhere else other than heaven? Well, paradise is somewhere else other than heaven. It is also on Earth, i.e. the Garden of Eden(In the New Heavens and New Earth, the whole Earth will be a paradise again, and we will "eat of the fruit of the Tree of Life"[see Revelation 2:7]). But that Paradise is not here yet. So, if there is another Paradise at this moment, it can only be in Heaven. It seems that there may be a Paradise in Heaven at the current moment, as detailed by the apostle Paul in 2 Corinthians 12:1-4, where he talks about how he was "caught up to the third heaven... caught up to Paradise and heard inexpressible words, which it is not lawful for a man to utter." However, I do not personally believe he was talking about an actual heavenly Paradise, because the apostle Paul had just said in verse 1, "...I will go on to visions and revelations of the Lord." So, it's possible he was having a revelation(through a vision given by Christ) about a future paradise on Earth(not that he was taken up to a literal paradise in heaven), but one can most certainly debate that. Either way, if you want to say that Paradise exists somewhere at the current moment, then there is absolutely no chance that you can say it is anywhere other than heaven.
So, do we have a contradiction between Luke 23:43 and John 20:17? Well, no! As I said in the beginning of my post, there is another valid explanation(other than moving the punctuation mark) that reconciles the two verses. All we need to do is prove that the dead are totally unconscious; we can do this quite easily. So, onwards and upwards!
Ecclesiastes 9:5; 10 "For the living know that they will die; But the dead know nothing, And they have no more reward, For the memory of them is forgotten."; "Whatever your hand finds to do, do it with your might, for there is no work or thought or knowledge or wisdom in Sheol, to which you are going."
Psalm 146:4 "His spirit goeth forth, he returneth to his earth, In that day have his thoughts perished."
Isaiah 38:18-19 "For Sheol cannot praise thee, death cannot celebrate thee: They that go down into the pit cannot hope for thy truth. The living, the living, he shall praise thee, as I do this day: The father to the children shall make known thy truth."
Yes, these scriptures make it entirely evident that the dead of totally unaware of themselves and their surroundings; unable to think, to have any knowledge or wisdom whatsoever, or even so much as hope for the truth of God. And that at the moment of their death, they return from whence they came(the dust), their spirit returns from whence it came(God), and all their thoughts perish entirely. But there is more to support this view; the fact that Jesus, Paul, and Luke referred to death as "sleeping."
John 11:11-13 "These things said he: and after that he saith unto them, Our friend Lazarus sleepeth; but I go, that I may awake him out of sleep. 12 Then said his disciples, Lord, if he sleep, he shall do well. 13 Howbeit Jesus spake of his death: but they thought that he had spoken of taking of rest in sleep."
Acts 7:59-60 "While they were stoning him, Stephen prayed, "Lord Jesus, receive my spirit." Then he fell on his knees and cried out, "Lord, do not hold this sin against them." When he had said this, he fell asleep."
1 Corinthians 11:30; 15:6 "For this reason many among you are weak and sick, and a number are asleep."; "After that, he was seen of above five hundred brethren at once; of whom the greater part remain unto this present, but some are fallen asleep."
I just want to stress how vital it is that the dead are unconscious so as to lend credence to these metaphors. The metaphor of death being analogous to sleep makes very little sense if death does result in unconsciousness. The metaphor becomes essentially useless, and quite confusing if I might add. During deep sleep, we are unaware of our body and surroundings, though not entirely unconscious, as there is still subconscious brain activity(this is, of course, due to the fact that the brain of a living person is not dead but still functioning. The brains of dead people are, however, entirely nonfunctional). It is an analogy, after all. No analogy, by definition, can be perfect. But if the dead were aware of their surroundings, in a "hell" or "paradise", then they would not be asleep; they wouldn't be anything remotely similar to being asleep(I hardly imagine you can fall asleep while being tortured by fire, or in the total bliss of a beautiful paradise in heaven with God Himself. I also hardly imagine that one can be woken up from either state). The analogy is reduced to utter meaninglessness.
There are two points Jesus is trying to make with the metaphor;
(1) The dead are unconscious; unaware of their surroundings, just as people in deep sleep are.
(2) The dead will awaken from their state of unconsciousness in the resurrection, just as living people are awoken from their state of sleep.
The power and beauty of these notions are diminished greatly(effectively to the point of nonsense) when you take "asleep" to mean either "being tortured day and night in hell" or "being in total bliss in a heavenly paradise." As Ecclesiastes states: The state of the dead is the same for all, as there is no knowledge, thought, or wisdom of any kind whatsoever for anyone at all.
Now that we have proved that the dead are totally unconscious of everything, we can see what Jesus was saying to the thief at Luke 23:43 in a different light, without having to alter the placement of the punctuation mark; a light that, I feel, shines a whole lot brighter.
Luke 23:43 "And Jesus said to him, "Truly I tell you, today you will be with Me in Paradise.""
So, did Jesus really mean that the thief would be with him in paradise that very day? Yes, and no!
For my first point: The word "day" doesn't always mean, "a period of twenty-four hours as a unit of time, reckoned from one midnight to the next, corresponding to a rotation of the earth on its axis." It's a pretty flexible term. Here are some additional definitions that are given by Google. (1) Day - "the part of a day spent working." Example: "He works an eight-hour day." (2) Day - "a particular period of the past; an era." Example: "The laws were very strict back in those days." (3) Day - "the present time." Example: "The political issues of today are tough." (4) Day - "the span of someone's life." Example: "She cares for him all the rest of his days."
Now for my second point. Jesus is never once recorded as saying, "truly I tell you today", as a form of emphasis. He says, "truly I tell you", or "truly I say" about 50 times in Scripture, but he never adds any kind of temporal qualifier. You and I might do that if we’re trying to convince somebody of something we’re going to do that we failed to do before. If your mate tells you, "You promised to do that before, but you didn’t do it." You might reply with something like, "Well, I’m telling you now that I’m going to do it." The "now" is a temporal qualifier used to try to convince your mate that this time things will be different. But Jesus is never recorded doing that. He says, "truly I say" many times in Scripture, but he never once adds "today". He never has a need to! He certainly didn't need to when he was speaking to the thief on the cross, because it was his first time ever speaking to him.
So, what's my interpretation? Well, I think that Jesus was speaking from the point of view of the criminal. What do I mean by that? Well, remember when we proved that the dead are totally unconscious? Well, then, at the exact moment of the thief's death, he would have blacked out entirely. And sometime in the future, many hundreds of thousands of days later, he would be resurrected. But guess what? From his point of view, but an instant would have passed. You try. Blink. Just once. When you're done, do you think you are on a day other than the one you had initiated your blink on? That'll be the viewpoint of the thief.
The thief would have absolutely no awareness of what was going on in between his death and resurrection because he'd be entirely unconscious. He could be dead for two-thousand, three-thousand, even a million years, and he would have no knowledge of anything at all during that time period; he would die and be resurrected in the blink of an eye. Knowing that; what do you think will be the first thought when he is resurrected by Jesus? "Oh my goodness, how many years have passed by, my lord Jesus!?" No, it'll most likely be, "What! I only died a second ago! My lord, you were right." From his frame of reference, not only does his death and resurrection happen on the same day; they happen within the same instant. From the thief's perspective, having no perception of any time between the period of his death and resurrection, and having absolutely zero knowledge of anything happening during it(as per Ecclesiastes 9:5; 10), his death and resurrection happen on the same day.
And that's what Jesus was doing; giving the thief a promise from the vantage point of the thief. Why? Well, even in all his suffering and anguish, with the weight of the world on his shoulders, Jesus could still dig deep into his heart and say something motivated by love and guided by the immense wisdom that he alone possessed. Jesus knew that from the criminal’s POV, he would be in paradise the very same day he died.; that there would be no perceptible gap in time between the moment of his death and the moment of his resurrection.
Jesus didn’t have the time nor the energy to explain all the intricacies of life, death, and the resurrection to the repentant man dying next to him. In one short sentence, Jesus told the criminal all he needed to know to put his mind at rest. That man saw Jesus die, then shortly afterward, the soldiers came and broke his legs so that the full weight of his body would hang from his arms causing him to suffocate to death quickly. From his point of view, the time between his last breath on the cross and his first breath in paradise would be instantaneous. He would close his eyes, and then open them again to see Jesus extending a hand to raise him up, perhaps saying, "Didn’t I just tell you that today you would be with me in paradise?"
While the definition of "day" Jesus was operating under isn't found in any of the definitions given above, my point was to show you that what one considers a "day" is very flexible. When Jesus said "today" to the thief, he meant something like "from your POV of what the current day is." So, Jesus was effectively saying; "Truly I tell you, from your point of view you will be with me in paradise this very day." As opposed to, "Truly I tell you, during this period of twenty-four hours corresponding to the rotation of the earth on its axis you will be with me in paradise."
I find this incredibly heartwarming. Of course, I certainly don't know that it's true. I just wanted to answer the question(of reconciling the two scriptures given) with a valid alternative to fixing an "incorrect translation", as you put it(and you can certainly make a very strong case for altering the punctuation mark. I'm not saying that you cannot. I'm just looking at it through another possible approach). Either way, whether you decide to alter the position of the punctuation mark or not, there is a way to reconcile John 20:17 and Luke 23:43. I hope this helps! Have a wonderful day. :)