Very few sims at parties I attend

Lately, when I go to other people's parties, I can only see the host sims and 2 or 3 other guest sims. I'm sure there are more sims there that I'm not seeing because the parties level up just fine. And also when I leave and come back with a different sim of mine I see the host sims and 2 or 3 different guest sims. (I have a recurring problem with not having access to party chats while using my wifi, so I can't see how many other players are attending.)

I think everyone else can see my sims, because I'm getting a normal amount of stickers, but this issue is limiting me in who I can give stickers to. Is anyone else having this problem? I looked on the bug report page and I don't see any posts that fit. I guess I can go ahead and create a new bug report, but I'm curious if anyone else has noticed this issue.

Thanks.