One Sims from Maxis Making a Splash Household completely changes appearance.

Ok, I have a bit of a weird one ...

I always play without any mods or cc and have all packs and kits downloaded and installed.

I wanted to start a new game with the Making a Splash household from the gallery. It's a Maxis created household and you can find it here: https://www.ea.com/en-gb/games/the-sims/the-sims-4/pc/gallery/DB9F4EC8983E11E98AFB60CCA9235FE7

The bug I'm experiencing has to do with this character:

I really like her, she's super cute, but when I went to put in a few other households to the game, I noticed that her appearance had changed to this:

So I replaced the whole household with the original from Maxis again, saved again, went to move other households in again, and ... she changed again:

What's going on here???