Just wanted to update everyone that a "penalty" system for failed connections will be implemented soon. This is not a "fix" but will hopefully cut down on games getting stuck because the same person(s) who has issues repeatedly attempts to join. A warning message will be issued so users understand they need to do something to alleviate the issue.
The penalty will not be too great, you can read the exact timings based on the number of attempts here in this pull request:
https://github.com/FAForever/server/pull/885