Means of identification
The biological body with five senses, touch, taste, smell, sight and hearing can identify a person.
The mind though immaterial is another means of identifying a person, key phrases, behaviors and/or mannerisms can bring into play memories which identify a person.
Morphing
Jesus Himself prior even to His resurrection transfigured or morphed.
“And he was transfigured before them, and his face shone like the sun, and his clothes became white as light.”
Matthew 17:2
Of Lucifer it is said he morphs
“And no wonder, for even Satan disguises himself as an angel of light.”
2 Corinthians 11:14
It’s important to note that at this point Jesus’ carnal/human biological body containing blood has been exchanged/replaced/upgraded
“It is sown a natural body; it is raised a spiritual body. If there is a natural body, there is also a spiritual body.
in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised imperishable, and we shall be changed. For this perishable body must put on the imperishable, and this mortal body must put on immortality.”
1 Corinthians 15:44, 52-53
Analysis
OP has highlighted three historical events whereby those close to Jesus did not recognize him.
John 20
Mary could rely on hearing, and sight to identify Jesus, as well as memory. We can establish that when Jesus called her by name He did not mask his voice and that instantly helped her identify Jesus by prior to that we are told she heard him, because they had conversation and she saw him because they were face to face. The language and wording would indicate they were close to each other.
Granted she was crying, this might have blurred her vision but His voice could not have been mistaken for another unless He had masked it by speaking in a different voice.
Logically it’s not a stretch to infer that Jesus looked different and/or sounded different that Mary did not know it was Him
Luke 24
The Road to Emmaus. Once again two men this time, in Jesus’ inner circle, maybe not two of the eleven but their remark about their “hearts burning inside” indicates that they were familiar with His preaching/teaching. They saw the man, he walked with them, so they could smell Him, they might have even touched Him when insisting He should stay with them for the night and share more Scriptures with them, they obviously heard Him and they had memories of Jesus.
And yet they didn’t recognize Him. While it’s possible that God blinded them from recognizing Jesus though Jesus was unchanged, it’s also possible they were not able to recognize Him because He was transfigured and unidentifiable to His former body
John 21
At the seaside. One thing that was most curious about this event is Jesus calls out to them and refers to them as “Children”. That phraseology is not typical of peers or men of similar age but of a senior to younger men. Even after John tells Peter it’s the Lord the text says something curious
“Jesus said to them, “Come and have breakfast.” Now none of the disciples dared ask him, “Who are you?” They knew it was the Lord.”
John 21:12
If someone is looking at a person that days earlier appeared in the room that was locked and He had a certain appearance and now they are looking at the same person but were thinking not to ask “who are you” because they knew it was the Lord, whatever gave away that it was the Lord wasn’t His appearance. He was clearly transfigured as looked and sounded like an older gentleman.
Conclusion
In simple understanding Jesus was not easily identifiable though His face was seen, His voice was heard because He was able to transfigure and take on different human appearances and speak with different voices.