The bug
There is a bug with the animations of chests and other storage blocks when they are opened at the same time that it enters a world border.
A video of the broken animation can be seen here: https://youtu.be/JgXPzXpJrM8
This issue is fixed upon reloading the world.
How to reproduce
Place a chest next to a world border
Type
/worldborder add -2 5
Open the chest so the animation is playing when the chest passes through the world border
❌ It should look like in the video: https://youtu.be/JgXPzXpJrM8
Please provide some additional screenshots or videos of this issue occurring whilst the F3 debug screen is enabled.