There may have been a power outage. I tried to disable this mount point protection, but it didn't work. In addition, I noticed that when executing the lsblk command, the "Read-only" flag was set to 1 for data_SSD512-thin_pool.something is tripping up the multi mount protection: https://docs.kernel.org/next/filesystems/ext4/mmp.html
do you have any custom setup that might interfere? changed hostname? time jumps? ...
Bash:
rpgadmin@rpgsrv:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 476.9G 0 disk
├─data_SSD512-thin_pool_tmeta 252:0 0 120M 0 lvm
│ └─data_SSD512-thin_pool-tpool 252:6 0 476G 0 lvm
│ └─data_SSD512-thin_pool 252:7 0 476G 1 lvm
└─data_SSD512-thin_pool_tdata 252:1 0 476G 0 lvm
└─data_SSD512-thin_pool-tpool 252:6 0 476G 0 lvm
└─data_SSD512-thin_pool 252:7 0 476G 1 lvm
nvme0n1 259:0 0 238.5G 0 disk
├─nvme0n1p1 259:1 0 1007K 0 part
├─nvme0n1p2 259:2 0 1G 0 part /boot/efi
└─nvme0n1p3 259:3 0 237G 0 part
├─pve-swap 252:2 0 8G 0 lvm [SWAP]
├─pve-root 252:3 0 69.2G 0 lvm /
├─pve-data_tmeta 252:4 0 1.4G 0 lvm
│ └─pve-data-tpool 252:8 0 140.9G 0 lvm
│ └─pve-data 252:9 0 140.9G 1 lvm
└─pve-data_tdata 252:5 0 140.9G 0 lvm
└─pve-data-tpool 252:8 0 140.9G 0 lvm
└─pve-data 252:9 0 140.9G 1 lvm