Photos on Iphone

Hoping someone can help. I have moved folders of photo’s onto MyCloud and can easily see them all on the laptop. The problem is I can see all the folders on my iPhone but only some folders are showing the actual photos. Does anyone know how to resolve the issue ? why are only some photo’s appearing in the folders while other folders are empty when they should have photos ?

Many thanks all

Hi, the following link should help you with this. 

“WD Photos does not display all the photos on a Personal Cloud drive or WD NAS drive”: