are there any other records after this ?
I looked at the list of updated packages and didn’t find anything that I thought might lead to this issue, but you can try rolling back these packages to the previous version:
extra/grub-btrfs extra/apparmor extra/timeshift-autosnap-manjaro
sudo downgrade grub-btrfs apparmor timeshift-autosnap-manjaro or use the cache of these packages (if you have one) from /var/cache/pacman/pkg/
since you have extra/grub-btrfs packages installed I suppose you can choose one of the snapshots in Grub boot menu, that’s right ? if this is so try to boot into one of them to check their health.
here is an example of recovering from a snapshot manually, because timeshift did not work in your case. but unfortunately I can’t guarantee the functionality of this method. Before doing this, you should back up all important files to the other volume https://gist.github.com/al-swaiti/2f571ffd506090d92bcb3cf9afb33066#step-5-restore-from-working-snapshot
or better [HowTo] Manual rollback with btrfs use this manual