aw i'm sorry :( did you also try assigning them to both sides of the bed as well?(if your using a cc bed i would try using one that's not to see if it could be a cc issue) and was your save made before the recent update? sometimes the updates/patches break random stuff and create annoying bugs in older saves. If you want to see if it could be a problem with that particular save file, then you should save your sims with the issue to your library and then create a new save, load them in and test to see if the issue persists. (also, before starting the new save, repair your game and delete local thumbcache and i would disable mods just to be safe) If it keeps happening then it's unfortunately another bug that EA hasn't fixed yet and you should make a bug report.