Sims Marriages End After Coming Back from CAS

Hey everyone,

Recently, every time I have left CAS while playing in a household (like when changing outfits), the sims in the household who were married aren't anymore, and I get a pop-up saying they just became partners. I have no mods downloaded and don't enter CAS with cheats; I just click to plan outfits on mirrors or dressers. 

This is so annoying when playing with families and in legacy challenges. Any tips to fix this?