Hello!
I took a screenshot and tried again in a fresh project and was not able to replicate the issue there, either. It appears to be a VisuStella MessageCore incompatibility. Sorry for the bother!
I would have liked to have been able to switch faces without any opening or closing/flickering in between, but with MessageCore turned off, this is working great (when the face is not changing).
Thank you for looking into this for me!