Hi,
it depends - where is your data stored?
We have similar problems:
We have a 15node cluster using ceph, so it is important to stop all VMs on all hosts, before the storage can be stopped.
Proxmox will shut down all VMs on a single host and then shuts down this host.
So it is possible that some hosts without VMs but with CEPH-OSDs are going down early and hosts with many or slow VMs cant reach their data anymore, which is bad....