PC - Unable to connect to friends after one match

Kadu

Step 1: Boot the game

Step 2: Join a friend or invite a friend

Step 3: Play a match with your friend or friends

After the match ends, on the end screen I usually get a grade error, and when I go back to the lobby I get a message saying "CONNECTION LOST - The connection to the party has been lost."

After that I can only connect to a friend again after rebooting the game.

If I try to connect directly through Steam using Shift + TAB and I'm able to connect, but they can't see when I'm ready and I can't see when they're ready, and if they join a match I just don't go with them.