My iCloud contacts has stopped syncing on macOS High Sierra (10.13.2). I've turned off Contacts under iCloud in System Preferences, restarted, even tried doing the same thing in Safe Mode. No matter what, Contacts show old contacts and won't sync properly. What should I do, short of turning iCloud off and back on? I've got 25k photos that will re-sync all over again if I turn off iCloud and back on, which will be incredibly long on my slow Wi-Fi connection. Thanks!