I've had a -- NOT consistent -- but fairly frequent and across several builds -- similar issue. Mine undresses me when I add to or cast a buff from the Skill Casting Tab. I know that sometimes this is very preferable, and that you guys are smart enough to have added a lovely checkbox in "preferences" for "Allow equipment changing while casting buffs." I have made sure the box was unchecked. I have also checked then unchecked the box to make sure the changes were saved (as I've also made sure was properly checked) and when I look at that box, it's clearly empty - not checked.
The interesting part is that it only seems to do it in the first day or two of a new ascension. Then it stops - whether I've been fiddling with it again or not.
I deliberately removed any auto-changing in aftercore for buffs, and I do it manually (via mafia, but *I* change the outfit and I purposely named it "NAME" so it doesn't even remind mafia of MP or buffs etc. When I do a run, I pre-set, before ascending, all of the automation to pretty much stop - even the NPC stores - until I'm sure I've got enough meat for them to, say, buy MMG in limited quantities with my approval.
IOW, I've done everything I know to do, I cannot reliably reproduce the issue, it happens across many many builds over the last month perhaps, and I just wondered if I'm missing something extremely obvious. This was the only thread I found in my search that even mildly relates to the same issue.
I'm not calling this a bug b/c I'm not sure that it's not something on purpose or that I've somehow screwed up. So - any thoughts welcome. Thanks muchly! Halle