iPhone photos suddenly stopped syncing with Mac desktop and will not restart

Hello dcmenne.

Welcome to Apple Support Communities.

If I'm understanding correctly, the photos on your iPhone have stopped syncing to your Mac. Keeping your photos up to date across all devices is important, and I will be glad to assist. You have already performed some great troubleshooting so far.

Have you checked to see if the photos from the iPhone are viewable at iCloud.com? If not, let's do that first by signing in, and selecting the Photos icon.

Additionally, please see the info below to make sure that you have not reached your iCloud storage limit:

Get help with iCloud Photos

"If you exceed your iCloud storage limit, photos and videos won't upload to iCloud and your library won’t stay up to date across your devices. To continue using iCloud Photos, upgrade your storage plan or reduce the amount of storage that you're using.

Reduce the storage for iCloud Photos by deleting photos and videos that you don't want to keep from your iOS devices or on iCloud.com. Your device will immediately remove any photos and videos that you delete and they won't be available for recovery in your Recently Deleted album.

If you're out of storage, your devices won't back up to iCloud, and new photos, videos, documents, and your information won't stay up to date."

Cheers.

Hi dcmenne.

Thanks for trying those steps. Next, I would suggest contacting Apple Support.

Here's how:

Contact Apple for support and service

Take care.