@Turjan - Okay, I don't yet know why this is happening. But I am almost positive it's not SP changing those traits, we would have had tons of complaints about that if it were a common thing. I would next want to know if this happens (and I know this would be a bit difficult to test because it's not easy to prove a connection if something doesn't happen 100% of the time) with only NRaas mods in play and no other. If it's really only happening to one household though, I would have to say something is not quite right with them.
The entire point of Rotational Play is that nothing significant, subject to the player defining what "significant" means, happens with households that are not in active play. Hairstyles getting messed up just as an example by comparison is not significant to me and those are easy to put right with no real impact on gameplay. Traits changing can be pretty significant under just about any definition.
Nothing interesting being reported on by way of Overwatch or ErrorTrap script logs?