Pages Problem - Syncing/collaborate with iCloud not working.

Hi guys,

I have a problem with pages using the iCloud sharing feature. I created a document, hit collaborate. Everything was ok and those with a link could access but recently they couldn't and I discovered it wasn't able to sync to iCloud anymore.

I tried this with a new document and the same problem. If I click collaborate it now says

"Pages couldn’t connect to iCloud. You won’t be able to edit this document until collaboration resumes."

I can't get it to work. I am connected to the internet, tried from my phone hotspot in case it was a firewall thing. At a loss now. I have also tried a restart/shut down etc. I cannot use pages collaboration feature.

Any thoughts on what this is and why its happened and what I could do?