icloud photos won't Sync, windows 11

Hi garethsnaim,

Check to see if security software may be causing communication issues with iCloud, as outlined in the following article:

Resolve issues between iCloud for Windows or iTunes and third-party security software - Apple Support

Test your connectivity

1. Check your hosts file to make sure that it's not blocking iTunes from communicating with Apple's servers.

2. If you’re having issues using AirPlay, Home Sharing, iTunes, or Remote, test the connectivity between the computers or devices in your house. They should be connected to the same network and subnet in order to function properly.

Test your security software

If you still have trouble after you test your connectivity, your security software could be interfering with your computer's connection with iCloud for Windows or iTunes.

In some cases, it might be necessary to temporarily remove your security software to isolate an issue. Some Internet security apps don’t uninstall completely, so you might need to download and run a cleanup utility for your security software for it to be completely removed.

Work with your security software provider to allow the complete list of ports and services that Apple products use or if you need help with uninstalling their software.

Reach out to Apple Support directly if the issue persists, as they'll be best equipped to help investigate the unexpected behavior with iCloud Photos. You can use the following link to reach out: Contact - Official Apple Support

Kind regards.