The verb "bara'" in Is 65:17 is in qal stem participle form . Quoting from an article precisely on qal participles :
A participle can also function as a verb in a clause. [...] Present
active participles express a "continuous" aspect regarding the action
of the verb (but the tense or sense of time of the action is
determined solely by context)."
That the "I am creating" translation is more literally accurate than the "I create" one is confirmed by its being the one chosen by the two most literal Bible translations: the Literal Standard Version and the Young's Literal Translation .
Possible solutions to the apparent problem
As already suggested in a comment, it may be that "I am creating" is a colloquialism for "I am going to create", just as people do in many languages (of which I can personally attest English and Spanish). Of course, this solution needs to be validated by an expert in biblical Hebrew.
2. Precise definition of what we are waiting for in 2 Peter 3:13.
2 Peter 3:13 can be interpred in the sense that we are not waiting for the new heavens and earth to be created but to be made available to us: they were indeed created when God spoke the words of Isaiah 65:17, but since that time they are being kept "in storage", hidden from us, until they are revealed and made available to us at the end of times.
3. Eternity of God according to classical theism (my favorite solution)
God is eternal, and in his eternity - which is one moment of infinite fullness, not an infinite succession of moments - He creates a universe which evolves in time, but God Himself is not in time. Time is an internal dimension of the universe, just like the 3 spatial dimensions. Thus, whereas God's viewpoint is in eternity, man's viewpoint is within time.
Appealing to an anthropomorphism, God, in the one infinite moment in which He lives, is holding in his hands the whole film of the universe from the Big Bang to the end of times, sustaining each frame in existence and having all the frames simultaneously before his eyes. In his eternity, God is creating the universe, is creating each human soul at the time of the respective conception, and is creating the new heavens and new earth, even if, from our viewpoint, they will come into existence only at the end of times.