How to stop WD My Cloud Scanning?

Have a WD My Clour 3TB with the latest firmware. This was working as it should , I have upload images and they show as thumbnals in both the phone app and dektop app.
Yesterday I uploaded more images and now all thumbnails have disappeared.
I did the following to see if I could correct the problem, Shutdown and then reboot.
Once rebooted the UI showed Idle and all thumbnails were now OK, however within a few minutes the UI showed it had gone from Idle to Scanning , once the scan had finished all thumbnails had disappeared !!.
Is there anyway to stop scanning taking place so I don’t lose the thumbnails ?

You can stop the scan/database rebuild process by turning off remote access. However, it will be resumed afterwards when it’s turned on again.

The current OS3 firmware update will rebuild the database in order to accommodate its new features. It’s best to let it finish.

Yes and as I said once the scanning has finished the thumbnails disappear !!!