No search from iphone

My Cloud EX4 12TB will not search from my iPhone. I keep getting an invalid operation error. Can not search music or movie shares. Please can someone tell me what I am doing wrong?

What app on iPhone are you trying to search with? My Cloud app?

Yes Mike I am using the My Cloud app from the Apple app store for my iphone 7 but can not search within files for a music song or movie title.

I just tried searching on my iPhone and it is easy. First of all you need to know where the Help for the app is. When app is turned on there are two menus for app. The 3-bar menu at top left can take you to settings for the MC. tap it to see Settings, and in there at the top is MC app Help which has lots of info.

The other menu is the 3-dot menu on top right of home screen. Use this when in your music or video files on NAS.
You should see the search box at top of list. I searched for a key word of song title and saw all choices.

Get familiar with these menus.