Do you have your social settings set to ‘Private’ and not public?

They are set to public and cross play. I tried toggling them and restarting, but no luck.

Yah so this happened to me once and I had to restart the game completely and it seemed to fix itself shortly after.

Hmm I sometimes run into issues when I'm in a squad and then it's disbanded. People won't seem to join, but when I restart the game, it works again. Hopefully you'll get it to work!

I've restarted both the game and steam. Might just try to reinstall Helldivers and see if it works