Did Jesus transform into spirit form after Resurrection In the 40 days after the Resurrection and before his Ascension, Jesus appears and disappears to people, including his disciples.

He also is not recognizable by some of his followers including Mary Magdalene at certain occasions until he identifies himself.

Is there any evidence or reason given on how Jesus' human form has now been enhanced with spirit-like powers?

Also - is there any information on whether Jesus stayed with his disciples or his mother during these 40 days, I saw this question, but I think there isn't any such information?
Probably the most definitive verse on this is in Luke:

36 While they were telling these things, He Himself stood in their midst and said to them, “Peace be to you.” 37 But they were startled and frightened and thought that they were seeing a spirit. 38 And He said to them, “Why are you troubled, and why do doubts arise in your hearts?
39 See My hands and My feet, that it is I Myself; touch Me and see, for a spirit does not have flesh and bones as you see that I have.” 40 And when He had said this, He showed them His hands and His feet. 41 While they still could not believe it because of their joy and amazement, He said to them, “Have you anything here to eat?” 42 They gave Him a piece of a broiled fish; 43 and He took it and ate it before them. Luke 24:36-42 NASB

Here Jesus affirms that a spirit does not have flesh and blood, but He Himself does.  To prove it, He tells His disciples to touch Him.  Then He provides another proof by taking a piece of broiled fish and eating it.  This is further proof because spirits do not and cannot eat physical food.
These appear to be just two of the many convincing proofs Luke mentions in the first chapter of Acts:

To these He also presented Himself alive after His suffering, by many convincing proofs, appearing to them over a period of forty days and speaking of the things concerning the kingdom of God.  Acts 1:3 NASB

So, no, Jesus was not merely a spirit.  His resurrection was a bodily resurrection.  However, just as before the resurrection, He was Lord of Creation and could do miraculous things.