Sim in household is not playable

Hello! So, yesterday I came to discover a big problem when trying to play with my new sim household in a new save. I created a household with two sims like normal, Erin and Tristan, moved them in and everything seemed fine. But then, I loaded into the game to play the household and suddenly, Tristan seemed like he wasn't in the household. He spawned normally, but I could not see his icon in the bottom left corner. I could only play with Erin. I thought that I could maybe fix it with a cheat, but I couldn't. I used testingcheats on and tried to shift click to add Tristan to the household but the option was not there.

I searched for answers online and already tried the following:

1. Delete save file and create a new one.

2. Delete all mods and custom content

3. Repair game

4. Uninstall the game and install it again

I tried to load into the household after reinstalling, the only thing I recovered back into the game were my save files so I could play the household. I currently have no mods or cc in the game, so those can't be the problem anymore. I don't really know what to do. The problem persists and I still can't play as my other sim.

I hope to find a solution here. Thank you in advance!