Re: Uploading Sims from the gallery does not work properly.
@PrincessofIron Do you have "include custom content" checked/ticked in your sorting filter in the in-game gallery (if this is where you are downloading the sims)? If so please try unchecking this and then search for households. If this does not work, please try downloading this test sim I have uploaded. I made sure that there is only base game hair and clothing on him. Please try downloading and placing him to see if the hair and clothing remains for you. Please let us know how it goes.
https://www.ea.com/games/the-sims/the-sims-4/pc/gallery/4B3B23770E6811EA859AF028EED69856