iCloud Drive won't sync any files - iOS 9

Hello,

I have a problem with my old iPad 3. Recently I restored it to the newest iOS available for this device (iOS 9). Everything works just fine except of iCloud Drive app. I've enabled viewing it from home screen and all I can see is just blank space. Absolutely no files. On my MacBook and iPhone I can see my stuff on Files app, but the iPad just won't sync. Is there anything I could do about it? I've already tried restarting, loging out but those aren't making any difference.

I'd really appreciate some help with this case :( Attached screenshot from my iPad: