Hi Se,
I am not sure, but it might have something to do with 3.4.There are changes being made to how Data is handled in Blender and 3.4 appears to be in a halfway state that causes many weird problems.
I would try Appending the model from before the Shapekeys in Blender 3.3 and go from there. If you’re lucky that might work.
Like I said, it’s just guessing on my part, that it’s a version-dependent problem, but I’m getting more and more convinced, while the reports of glitches and crashes with 3.4 accumulate….
