NFS stale file handle when mounting a usb disc via nfs

I have an orangepi pc+ which (among other duties) exports my usb (/media/wd/Music) drive with nfs.

The external usb drive (A Western Digital) automatically enters sleep mode when it is not used for a while.

When I try to mount that nfs-share on another machine, I hear the drive spinning up (awakening) and the mount succeeds.

But when I try to access the mount I get "ls: cannot access /opt/music: Stale file handle"

I had the same drive and /etc/exports on my raspberrypi-2 but there I did not have this problem (I could hear it spinning up as well when I accessed the mount so I know it was entering sleep mode as well). So I think it is a difference in configuration between the default debian install (not raspbian) on the raspberrypi and the armbian install on my oranpi pc+ but I don't know where to look.

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The line in /etc/exports:

/media/wd/Music 192.168.0.0/24(rw,sync,subtree_check,mountpoint=/media/wd,all_squash,anonuid=65534,anongid=65534,nohide,insecure)