Photos not working after iCloud backup restore

Hi,

I set up my new 8 plus using iCloud backup. Everything is fine apart from my photo collection isn’t showing up- all I see are gray thumbnails, some with the cloud icon, some without. It’s been like this for 4 weeks now- I’ve tried turning off iCloud photos and resetting the phone and restoring again from the iCloud backup, but the problem remains.

One weird thing I noticed was that when I switched iCloud photos off and and then back on again, I got the message that my photos would sync once the restore finished (this was 3 weeks after I set my phone up), but when I look at iCloud backup in settings, the phone has finished restoring and is making new backups. I’ve included some screen shots below. First is my photos app, second is what I see when I look at iCloud back up in settings, and last is what happens when I turn iCloud photos back on.

Any help much appreciated.