Game restarted and self-played
3 pod in Commander Open Play
I play Golos superfriends, against Sisay Legendary, against Meren. It started to get buggy mid-game when the Monarch was introduced (which messed up the card alignment).
My board became insane with multiple walkers, enchantments, and creatures. There were about 60 permanents on my field including emblems, then I ultimate'd Sorin, Grim Nemesis, after Primeval's Glorious Rebirth, multiple instances of Ajani, the Greathearted proliferating as well as Nicol-Bolas, Dragon-God proliferating too using that same effect. Sorin's ulti would have created about 60 vampire tokens.
The game then stalled, then restarted, and began to replay the first four turns by itself.
Never seen anything so crazy in my life.
Error report has been sent after the game crashed.
It sounds like you may need some more troubleshooting advice, please submit at: https://mtgo-support.wizards.com/hc/en-us/requests/new and select 'Technical Troubleshooting'.