Comment # 40 on bug 1209457 from Neil Brown

Thanks for the testing and packet capture. Unfortunately I cannot see anything
interesting in them.  As you say: the showmount and the mount;ls do actually
work in both cases.

You say that with 55.3 commands are less "reactive".  I assume that means the
response is slower.  I cannot see any evidence of that in the trace - replies
come within milliseconds.

There is a known problem with QNAP which is triggered by a recent change in
Linux NFS.  We do have the fix to avoid triggering this bug but I don't think
that update has been released yet.  Once you get a kernel that was released
after 22/Mar/2023 QNAP should be fine.