Comment # 4 on bug 1167079 from Franck Bui

(In reply to Jiri Slaby from comment #3)
> I am slow at rebooting the machine as I have zillion of windows open. But
> reverting the kernel didn't help. Where can I take older systemd?
> 

You can try to find old packages at http://download.opensuse.org/history/

> BTW I updated the nfs server on:
> 2020-03-11 08:04:04|install|nfs-kernel-server|2.4.3-12.1|
> 
> the client:
> 2020-03-02 07:01:04|install|nfs-client|2.4.3-12.1|
> 
> Could it be also the nfs server update?

Yes I would definitively give it a try too.