Client: Unplugging a second monitor crashes the game & Client: Reconnect does not work

After beginning to load into the game following champ select (before it showed the loading screen), I unplugged my second monitor. The game got stuck on a black screen and I pressed cmd-alt-esc to exit fullscreen. I had disconnected from the game. Now when I click reconnect it says "check your internet and try again."

I have had issues for months where, if I for any reason fail to connect to a game, it is 100% impossible to ever reconnect. I can start another match on a second account and connect, but never reestablish the first game. This BUG in the client has led to dozens of emails with riot support and several leaverbuster restrictions. Riot keeps telling me it's my internet. At this point, I'm pretty damn sure it isn't, considering this disconnect is the result of unplugging my monitor.

EDIT: Was able to reconnect about 5 seconds before /remake vote was completed. Still doesn't explain why I could not reconnect immediately.