I never allow auto upgrade because of stuff like this. I forgot to uncheck it this time. Maybe on betas it should be off by default! I have a proxmox snapshot to roll back to so not that big of a deal for me. Maybe you should also make a proxmox image available.
I have tested most betas since 2008. I have never seen so many failures as I have in the last year or two. Until I see better results I am no longer testing and wasting my time.
Thanks