I was playing on survival mode and i noticed that many pokéballs has no 3D texture while hold in the hand. And in the third-person view is the item bigger a useally. I thought it was maybe from optimized mods like optifine or Magnesium ect. I create a test instance to make sure there is ONLY Pixelmon on test instance.

Here the screenshot:
Third-Person view: https://imgur.com/a/Y03z1T1
First Person view: https://imgur.com/a/Q5zhsgp

Marking this as a duplicate (and unmarking as security. Please don't check that option unless a ticket contains an exploit/personal information)

The Pokeballs were changed to be a sprite item in 9.1.0 as mentioned in the changelog. I will link the original ticket with the weird size of the sprite however. Seems to be a bit odd. https://pixelmonmod.com/tracker.php?p=2&t=19571