This happens in my game when my sim moves into the dorms. It seems like moving into a place with roommates resets your household for some reason. She went back for a second degree and it happened again. I didn’t have this problem when she lived off campus. I’ve completed the insect collection for the third time now.
The only thing is I didn’t make any changes to my household. All I did was send my sim to university and have her live in a dorm. She didn’t have any career unlocks at the time so it only affected collections because that is all there was.
All household collections reset for me everytime I send a sim off to University or move a sim out.
BUT I also lose all the books I've written, lyrics and songs I've licensed, videos uploaded. My Sims have lost dozens songs, books, videos and of course not earning income from them. So everytime a Sim leaves the household ALL collections reset (books, songs, videos, household).
