I have found that with mutable-generated skeletal mesh, it will have strange deformations, such as vertex weights that have been incorrectly calculated [Mutable BUG 001]

Mutable currently does not automatically detect if a SKM has more than 8 bone influences per vertex. Probably what is happening here is that your SKM has 12 influences and those larger than 8 get remapped to other bones. You can manually change this setting in Engine\Plugins\Mutable\Config\DefaultM…

UE5.5 Mutable Skin BUG

Development Character & Animation

gustavorios2 (Gustavo Rios) March 9, 2025, 4:51pm 3

I have the same issue.
it’s broken.
I just reported a bug, still waiting for a response