Apple's Contacts app has been acting up for me recently. About the same time that iCloud sync stopped working I noticed that when assigning photos to contacts, they don't stay saved. They appear to be saved at first but when returning to the same contact card a minute later or so, the photo is gone.
Is anyone else having this issue? Any ideas how to fix it? I'm using macOS 10.13 on a 2017 MacBook Pro and iOS 11 on an iPhone 7.