[HELP] Cloth meshes not falling correctly

Hi, I’m currently working on a project to make the blanket fall on objects naturally. I imported my cloth meshes from Blender, but here’s the problem:

When I didn’t brush the whole blanket, it looks naturally like blankets. But when I painted whole blanket to 100, it looks like a plane and not moving.

Also, even though I enabled gravity, the blanket simply float over the objects rather than fall on it.

I’d be really appreciate it if anyone knows how to solve it!

Hengjian