I have the same issue with moving a disk.
For me it is not possible to move a disk to the lvm-thin storage.
"udevadm trigger" didn't work for me.
demesg:
[Tue Apr 14 18:26:29 2020] INFO: task systemd-udevd:9740 blocked for more than 483 seconds.
[Tue Apr 14 18:26:29 2020] Tainted: P...
Crucial are the omping tests!
https://pve.proxmox.com/wiki/Multicast_notes#Using_omping_to_test_multicast
Are there switch configs which restrict multicast?