So I MLB'd the bronze CE now that I'm done with bronze medals and I put it on my Vlad, but as far as I can tell, people who are seeing my supports only see it as a non-MLB version :V At least this is what 3 of my friends have told me over discord. Also, the skill levels on my Hans apparently never increased from 2/8/1 for them either, even though I did that last night as well and his third skill should be at least 7 or so.
No idea what's up with that, I don't even still have a non-MLB bronze CE anymore. I only ever got the 5 copies.
Edit: Fixed it by swapping CEs and servants around for a couple minutes, then they told me it got unstuck and was updating properly. That's really strange.