Hi Ehangal,
Let's review the information below to see if checking iCloud storage resolves this. 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 and iPadOS 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.