I have noticed that when changing a skeletal mesh asset via blueprint, the materials don’t update with it.
Relevant: Can't correctly change material after changing skeletal mesh - #6 by mharrison920
The best solution I’ve found is this: Can't correctly change material after changing skeletal mesh - #10 by Alex_iceman
We ended up ordering custom code to fix the issue on our end. But since the post can’t be deleted, it will remain, if only to maybe bring awareness that this happens at all.