iCloud has plenty of space but not uploading

Go to system settings > General > storage.

What is the size of your photos? If it's substantially all of your free space or larger than your free space, you will not be able to sync your library.

Also, if your device is nearly full, some syncing features may not work properly. You may need to free space on your device.

I'd start by first checking the sizes

Then, I'd restart the Mac, open photos, and see what happens

Zoe_Sas Said:

"iCloud has plenty of space but not uploading"

-------

Thank you for the screenshot.

Try uploading it in bulks --select a lot of items, and proceed from there.

Evidently you do not have enough space to sync all of your photos and videos