Not photo's NAS snapshots of your folders. The NAS takes daily snapshots of your files just in case. It gets deleted when the NAS is low on disk space. The action of Windows caused to NAS to lose 1 TB of disk space and thus had to free the snapshots.
[–] Chiefpacman ago
Ah, my mistake. He's right, that does sound a little like it's tryimg to index your folders, maybe?
Hope you figure it out