Title, Not enabling physics but leaving it affected by gravity makes it float, Enabling physics will just make it ragdoll, but fall, as desired.
Gravity is part of physics simulation. You need to enable physics to have it fall. In that case, you can create a complete ragdoll in the physics asset, or if you dont want a ragdoll, just add a single shape like a sphere.
Alternatively, you can simply apply your own gravity by moving the actor yourself every frame and avoid physics altogether.
A third choice is to use the Character Movement Component. It applies gravity “manually” without simulating physics too.
This is vague to me. Is this character? Why aren’t you using the Character class to utilize the Character Movement Component?
Is this not a character? Make new/modify the physics asset in PhAT so it’s one big collider instead of many. Plenty of adjustability in that area.