NFS fails to export/manipulate a share

I am running the latest Rockstor based on Leaf 15.2
Since a random moment in time I cannot alter my NFS exports regardless I ad/remove a share or change sync/async

After a fresh re-install I managed to export several shares but at some point the error came back.
The WebUI reports " Unknown internal error doing a POST to /api/nfs-exports " and I cannot see anything in the log (dmesg, journalct, /opt/rockstor/var/log/rockstor.log)

Is there any place I am missing which could give me access to logs and bring me a bit more clarity of what is the reason for those errors?

As usual any hint would be more than appreciated.