Ideas
I have an old save where this happens, but it has mods and I think possibly baked in bugs from it's age. I started a test save to work out what issues were related to the old save and if I should abandon it. That save uses a few mods, no cc. It's a rotational save. The test save has no mods or cc. It had this issue at the beginning while the two main sims' romance skill was low. Once it was up, I haven't had too much trouble as long as they interact occasionally. I set their romance like/disklike to favor flirting and affection hoping I wouldn't have to do to much to keep the romance level stable. So far so good. I have not moved on to rotational play yet. In the old save, I've had so many other things happen that I suspect is from rotation (ex pimples and crushes don't go away if the teen ages up while rotating; a happy couple shows up at the romance festival and proceeds to argue and fight until they hate each other, etc.) that I expect these two will have trouble when I do start to jump families. We're supposed to be able to rotate families without problems. I prefer rotational play. I probably will abandon the old save. I won't use the test as I like the few mods I use. I'll probably switch to sims 2 style rotating and see if that helps anything. Based on theses comments I'm not optimistic. The other thing is, on the test save when I do stumble into situations reported here, like the wandering bar tenders, I immediately save and send the save link to the moderators (or whatever they're called). Anyone who doesn't use mods or cc should do that too.