Nothing saves from playing online

So whenever I join and play another persons game, anything that I do never carries over to my game.

For example, when I leave from someone else’s online game and continue my game as solo, any guns I’ve collected, money I’ve earned, quests competed, etc. are all lost and reset to what I had before joining the online game.

Anyone else having this issue or know how to fix it?

Really?? no one else is having this problem?

It’s so frustrating, it completely ruined my game by making it pointless to play online with anyone.

I have the same problem but on PC no idea how to fix it either

Still haven’t figured out a way to fix it, aside from deleting my game and staring completely over.