Cache filesystem is going read-only:
Jan 3 10:15:06 Utopia kernel: BTRFS: error (device nvme1n1p1) in cleanup_transaction:1942: errno=-28 No space left
Jan 3 10:15:06 Utopia kernel: BTRFS info (device nvme1n1p1): forced readonly
Likely from getting out of space before, best bet it to backup and re-format the pool, you should never completely fill up a COW filesystem like btrfs or zfs.