GUI reports occasionally failed nodes

Hi,

I have some weird behaviours with PVE 3.3-5.
Occasionally, GUI reports failed/red nodes in our PVE cluster. After some minutes all nodes return to green state again.
This behaviour typically occours while having connection issue with NFS (only used for backup, templates, ISOs).
I see following in message log:
kernel: ct0 nfs: server xxxxxxxxxxxx not responding, still trying

NFS server is on another location which is why it sometimes can lose connection, but should this have any influence on the overall cluster health?

I use these NFS parameters on my NFS server:
rw,async,no_subtree_check,no_root_squash

Any ideas? :)