Unable to Join following game

I can join games freely with no problem, play one game, then afterwards I get the ‘Unable to Join Game’ message for every single game I try to join.
The only way I have found to solve this is to close starcraft completely for 10-15 minutes and maybe I am able to join a game by then.
This started sometime last week, but I only really noticed the issue over the weekend while trying to play, haven’t changed any settings so I have no idea what would be causing this problem.

Got the same issue.
It has been months but no one fix it.

You can try my solution in here