iOS 13: Photos says storage is low, pauses updates.

I updated to iOS 13 a a few hours after release and are experiencing problems in Photos. I have iCloud optimization turned on for my image library of around 10,000 pictures (all of which imported fine during upgrade).

For some reason, at the very bottom of the Pictures view my iPhone reports having paused updates due to low space, when in fact this is not true.

I have not uploaded hundreds of images, ot anything like that. I just snapped a few new ones.

I have around 5 Gb free space, as reported when clicking "Manage storage". That should be more than enough?

When sharing iCloud albums the iPhone also reports not uploading due to space restrains on the phone (my iCloud has 1,8 Tb free space).

Things I've tried:

1. Reboot, both normal and forced
2. Turn off and on iCloud photos.
3. Plugging into power

When I look on my other devices (laptop + ipad) the photos have indeed synced so I guess the consequences of this bug aren't too bad, but it's still a bug?

Any advice or confirmations?

/ J.