From the screenshot it could be a single vertex weightpainted to the hand.
Try this real quick.
Make a version of the asset with removed weight paint.
Enable the cloth and place it on there.
See if without weight paint the hand is still catching onto it somehow.
If it doesn’t, it’s a weightpaint issue.
You can look at the specific hand vertex groups to figure out which one went rogue.
If it does… please share a screenshot, that would be interesting to see…
Particularly because the cloth won’t follow the arm up.