VM failback with cloudinit and ZFS replication fails

This is a 2-node cluster running pve 9.1.5 with one additional QDevice. ZFS synchronization and migration generally work without problems. If a node fails, VMs with cloudinit are restarted on the remaining node. So far, so good. However, when the failed node becomes available again and VMs are supposed to be automatically migrated back to it, this fails. Every 10 seconds, a new migration attempt…