Wither Skeleton Skull Vision Glitch

Summary:

I noticed that when I place the skull of the Wither skeleton somewhere, the skull stays clear for a very short period of time. When I used slow motion, I found that Wither's skeleton skull was turning into an ordinary skeleton skull, and then it turned into Wither's skull.

Expected Results:

Wither's skull is dark, so the texture error shouldn't occur, just change to the common skeleton skull