Sims 4 PC, Sims changing into costumes randomly with MC Commander Center mod?

Help! I've had the MC Commander Center mod installed for a few months now. It's only in the last couple weeks I've noticed this glitch. NPC Sims I see around town are randomly wearing stupid, ridiculous costumes! (I'm not a fan of costumes in the game.) Clowns, hot dogs, weird conical hats, and all age groups are doing it. I have to manually go into the Dresser on each individual Sim and change their outfit. I then use Dresser to SAVE that new, normal outfit. Yet, later on I will see that same Sim with ANOTHER stupid costume! This is not for special events or situations; they're wearing costumes as everyday clothing.

I've tried every Dresser and Cleaner setting I can think of to stop this from happening, including Blacklisting items. But there's no option to Blacklist costumes that I could find. It's driving me insane, because I just hate the way it looks, and it does not fit my personal Sim world. I don't want to remove the mod. I prefer to actively play only one household, so the mod allows for a lot of control over NPC activity and neighborhood progression. It's just this one glitch!