Entities are rendered differently from 1.21.4 to 1.21.5+

1. Create a 17 x 27 x 8 box

2. inside that box fill the entire thing with item frames on every block

3. then create a map that has a solid color, and fill every item frame with the map.

Basically in 1.21.4 when looking at this box, the game renders all the entities pretty well, and my frames are not impacted (they stay at a consistent 180 fps when I’m looking at the box from outside, and when I’m inside the box it stays at around 230 fps. However, when I update to 1.21.5 my frame rate takes a massive hit.

When you are looking outside the box, my FPS ranges from 40-50. When you’re inside the box, it’s not as bad I still sit at a consistent 90-100 fps.

1.21.6 pre 3 still does the same thing