System not boot root-fs. I have to select a BTRFS snapshot

Hey,

Basically, all was fine. I ran an update using “yay”. My root disk was full. Deleted a few snapshots and re-ran yay. It worked. Did a reboot and suddenly my system does not boot but show grub screen with snapshots.

How can I set my recent snapshot as default live boot?
I have snapshots through timeshfit and I have restored from it previously. However, this time when I restore from snapshot the new snapshot is not becoming default boot.

Turns out my backup was corrupted. I used an older one and it worked thru Timeshift. I extended my rootFS to avoid the issue in the future.