Client Froze Mid-Game (ARAM) For Multiple People, Couldn't Reconnect, Then Game History Disappeared

This happened during an ARAM I played with 2 friends, so I know it wasn't just a bug for me.

As my team was taking the last nexus turret at about 15 minutes, I started using my Jhin ult to zone the enemy at their fountain. Right as I started firing, the game froze. I restarted the client and tried to reconnect to the still on-going game (even though it SHOULD have been over at that point regardless of my DC), but all I was getting was a black screen instead of the game. I tried switching to the legacy client to load the game, and kept getting the same black screen.

I checked with the friends I queued into the game with, and they experienced the same thing. After some time, the client stopped giving us the option to reconnect to the game, and now we can play other games. But there seems to be no record of game that froze in the client or online now. Not sure what would have caused this issue, but I hope it doesn't happen to anyone in a ranked game.