sys.dm_io_cluster_valid_path_names returns no result

Hello,

in a series of "identically" configured sql failover clusters I have some where this query does not return a result: 

SELECT path_name FROM sys.dm_io_cluster_valid_path_names;

The SQL failover clusters run without any problems. A backup tool used can back up the data, but when restoring I get the error message that the "drive\directory..." of the database files on the active cluster node cannot be found. If I execute the statement on this cluster node, I also get no result. 

These are not AlwaysOn clusters and also not clusters with Cluster Shared Volumes (CSV). The data volumes are provided as shared volumes in a directory as hard link attachments. They are therefore only ever active on the active cluster node of the respective SQL instance.

Has anyone ever had this problem and can tell me how it happens and how it can be solved?

Thank you

Jan