Linstor Resource Status Skip-Disk

I'm running three nodes with DRBD9.1.18, two diskfull, one diskless, and 
Linstor 1.25.1.
One of the storage nodes had a problem, after several reboots drbdadm 
status showed "diskless" on the node. drbdadm down res ; drbdadm up res 
resolved the situation, the status is UpToDate Secondary as expected again.

Linstor still shows the resource as "UpToDate, Skip-Disk (R)" for that 
node. What does that mean, and how to reset that status? Restarting the 
satellite didn't help.

Regards,
Andreas