[CentOS] nfs-server.service start delayed 60 seconds asking for password?

Hi,
when I start nfs-server.service it takes 60 seconds until the nfsd
finally is up. Looking at the process list I see a process
'systemd-tty-ask-password-agent' running which goes away after the 60
seconds the startup requires.

Does anyone have an idea what the reason could be for this and how I can
get rid of this delay?

Regards,
  Dennis