Morph Targets affecting vertices they couldn't affect

I have set up sliders to modify my characters appearance with morph targets. Up until 4.10 it all worked out great. But since 4.11 the sliders/morph targets are affecting vertices they couldn’t even affect.

For example: If I drag the slider for the height of the eyes, the shape of the upper body and the hair is also changing. Both of which are different skeletal mesh components… and these components don’t even have morph targets. Did I miss something here?

Additional Info: The upper body-, hair-, etc.-components are slave-components of the head (which has the morph targets)

Thanks in advance.

Edit: If I check “Disable Morph Target” inside the slave-components, they won’t get deformed. But is this really the solution? It seems like a bug.

I met the same problem and stuck for many days. The solution is simple, just un-check the “preserving smoothing group”,but I still don’t know the reason.