1.18.2 Optifine
Looking slightly above the wither storm will cause it to disappear (stop rendering)
This issue only exists when optifine is loaded

If you are on the ground then it is not a big problem
but if you are too close to its head when being picked up by the tracktor beam then you can't see its head

nvm I just found out that it is a already known issue
But still, please fix this

It is impossible for the author to fix this trouble. Optifine changes the "construction" of the entity renderer, so the author cannot fix it.

I'm not able to as this is something optifine internally changes with how the game renders entities. You should try bugging optifine about this.