Can't join friend - Unable to connect to game session

[76561199385042474]

Hi,
I have a very weird problem. A friend and I:
- are sitting in the same room
- are connected to the same router and so use the same internet
- have the same laptop model
- can both join public sessions with other players, but never the same

We can't join each other's game sessions and we both get the same error message: "Unable to connect to game session"

Only difference was that I used Norton 360, but I uninstalled it because I thought that it might cause the issue. It appears this is not the case, as the problems continue.

One thing I noticed: my friend always gets thrown into public sessions with 20+ people, while I only join sessions with 4 people at most.
So whatever is going on, my friend seems to be more "normal".

Already checked NAT type by the way.

All other games we've tried work well together, it's just this one so far.

Any ideas?

[🆄🅽🅲🅻🅴 🅹🅾]

Send a game invite over Social club, done.

[76561199385042474]

Originally posted by 🆄🅽🅲🅻🅴 🅹🅾:

Send a game invite over Social club, done.

Same message as before: "Alert - Unable to connect to game session."

[76561199385042474]

Okay, solved it. Posting it here because it might help other players.

I noticed that it were always the same few players I played with, no matter how many new sessions I joined. So I figured that what I had was not completely uncommon, there are between 5 and 8 players with the same issue at any given time.

Had a feeling my game wasn't up-to-date. Tried updating, Steam said it's updated. Checked the folder size against that of my friend, noticeable difference.

Verified integrity of game files. It seems it was not updated after all because it had to download quite a bit.

Everything works now. I hope this can help someone in the future.