UE 5.4 Metahuman props disappearing

The props attached to the metahuman blueprint keep disappearing.

In UE 5.4, I’m keyframing some metahuman animation in Sequencer. Does anyone know why props that are “Parent Constrained” in the view port or “Attached” in the Sequencer keep disappearing? Is there a fix so props will not disappear?
Sometimes the props disappear when I open the project the next day.

I have to re-attached them or re- parent constrain them. They work for a little while, then they disappear again… over and over.

Opening and closing a project also causes the prop to disappear.