Hi, this is a common problem. You are currently trying to add a new capsule collision which supports physics but it has nothing to do with the bones or body constraints. For some reason, UE4 needs bone constraints information in capsule collision to communicate with the cloth physic. You can see this clearly in the graph.
There are a few steps to do so. This solution also has been explained in an Unreal Livestream on Youtube.
Here, take a look at the Livestream which explains how the capsule collision should be created.
Hope it helps… 