I was playing again a bot pile and was nearing the final rounds. It froze when I had only 2 bots left to defeat and is stuck on the "starting round". I was hoping it would fix with rollover but there's no change.
I've encountered this glitch again. Much earlier in the round this time. It freezes a player out from getting more companions into the round, gaining paws, changing companions. However, it seems the game must continue playing in the background because if you exit after an hour or so you can still get Arena tickets if you place high enough in the ranking. You can't see or interact with the game though beyond that "Starting" screen so placing above 8th place is unlikely