Shared Albums on iPhone - don’t upload & all photos & videos show as white thumbnails

I first noticed my new photos in my shared albums don’t upload anymore (without getting feedback, I just realised they didn’t appear on new devices).

To trouble shoot I turned off sharing photos on my iPhone, restarted my iPhone and turned it on again.

Now ALL my Shared Albums won't show ANY pictures. They now ALL show as white thumbnails. This includes albums that I've shared as well as albums that I'm a subscriber to.

I can see some shared albums on my iPad. But even there some albums show white thumbnails only.

Can someone please help? This is beyond frustrating 😔