can't sync Contacts between iPhone <> Macbook Air

I haven't been able to sync Contacts in a few months. I have

-- an XR running iOS 13.6.1 and

-- a 2014 MacBook Air running Catalina (10.15.6)

I have checked all of the settings on both devices. I've turned devices off and back on. I have logged out of my iCloud account and back in (a few times!). When I updated my profile photo on my laptop, it updated immediately on my iPhone...but Contacts won't update.

I'm stumped. Help - ?