Hej again,
I guess the above puzzle can be left unresolved and the thread can be closed.
This situation made me to rethink general layout of our cluster and now I created setup with dedicated login node among other things. This solved NFS home file system issue and to my understanding is in general a better way of handling things.
One little comment. Currently, after fresh installation the qlustar-initial-config script fails due lack of space needed for apt upgrade part. Easy solution is to increasing FS size before running the script.
Cheers, Iggy