Hey, for future ref, this bit me on an animation project.
On just a couple of the dozens of squences where I baked animation on an Sk Mesh with “Edit with FK rig”, this bug popped up and would kill the level sequence. (Unreal 5.0.2)
I was able to fix the problem by baking the animation on the SK mesh to an Animation Sequence, adding that sequence and deleting the FK Rig. Was a quick solve thankfully as the possible destruction it would wrought was big.