Let me state up front I am not attempting to list every possible way to attempt to fix macOS contacts not syncing. There are plenty of other pages on the internet to help you with that. I’m only trying to list what helped me, and nothing else. The following instructions come from idownloadblog.com and are…
How to fix “button customizations not working” on Logitech MX Master 3S for Mac on macOS Ventura 13.3.1 (a)
Reboot your Mac. Hoping to getting it further narrowed down so that a reboot isn’t necessary (and I have seen it come back spontaneously too, if you wait long enough), but I can say with certainty that a reboot fixes it.