This topic has been discussed many times before on this forum. Search for your issue before creating a new thread. Here’s some helpful replies from other posts that you can use:
I turned on the decomposition geometry setting and it fixes the collision mesh issue but many things are off. Things are miscolored and avatars are invisible except for the head. Is this normal?
The colors are what showing the decomposition geometry is supposed to do. I’m not really sure how it fixed your issue because that’s just supposed to show the collision model.
Showing the decomposition geometry is just a way to visualize the hitboxes. It’s just a studio setting and players won’t see it in-game.