If I take a screenshot on my desktop or save an image from Preview I cannot upload these images to my Photos. If I drag them into the Photos app on Mac they will not sync to my devices. I also tried uploaded them using the iCloud website but the website won't accept these images. They stay grayed out when I choose to upload images. Does anyone know how to resolve this issue?
I had a issue like this and I do not know exactly how this fixed it but I went to the Apple in the left corner clicked it, then About this Mac. Then clicked the tab Storage. Then clicked Recommendations and did what it said there.Then made sure all the settings had a green dot. That did make my iCloud photo and MacBook Pro work better together again. I also upgraded my storage space.