iCloud Photos has to be enabled on each device for syncing to work.
iCloud Photos lets you see the same images and videos on all your devices connected to the same iCloud account and with syncing for Photos enabled. If you aren’t seeing synced media, or your media isn’t appearing at iCloud.com or on other devices, try the following.Check that syncing is enabled
You should first make sure that a setting didn’t get turned off for some reason:
iOS/iPadOS: Go to Settings > Account Name > iCloud > Photos and enable Sync this iPhone/iPad. (The text varies in older versions of iOS/iPadOS).
macOS: Go to Photos > Settings/Preferences > iCloud and check that iCloud Photos is checked.
If it’s checked in all the above, there are no additional options to configure or test in iOS or iPadOS—contact iCloud support to get assistance, as it may be account-related.Check the System Photo Library choice in macOS
With macOS, you can check and fix one additional element: In Photos > Settings/Preferences > General, the button labeled Use as System Photo Library should grayed out, which indicates that the currently selected Photos library is being used as the system library.
