Weird collision issue

So I’m posting for a buddy, apparently BA doesn’t have a language option unfortunately.

Anyway, from what I can tell and know, it’s an issue with a pattern on the jacket, which is a separate mesh ( and also split into many pieces) I know nothing about animating or collision issues but here are some pics and a .blend. Any help or suggestions is greatly appreciated!

Genes_Jacket_maniche_strappate_gioco_rosso_interno.rar (2.0 MB)

Does the coat have a cloth sim?

Is it rigged?

What is the setup here?

If it is rigged, have a look at transferring weights from the coat to the pattern:

The pattern is only a little out - a few millimeters, but it is enough to look wrong.

Maybe it can be fixed with a shrink-wrap modifier.