Average disk space used this month graph

this is the reason of not updating stats. The filewalker is doing a similar command, so in your case it took more than 48h to complete. Seems you either use a BTRFS, or your disk is SMR.

this is only confirms the slowness of this disk.

You may try to re-create a database storage_usage.db, but backup it first. You likely will lose a usage history after re-create of this database.

The disk is CMR and QNAP NAS uses ext4.
If I re-create the storage_usage.db I assume I will only loose history, not associated earnings? :wink:

Yes, you will lose only history. Just make a backup of this database on any case to be able to return it back if this workaround would not help.