Contacts screwed up - now won't sync between Mac and iOS

I recently installed TurboTax which installed a .llb file as an “update” that screwed up my computer. (Shaking fist at Intuit). I had to nuke and pave it. After re-install, all my contacts were duplicated. Using the “Find Duplicates” (and merge) screwed all the contacts up – everyone had the same name.

I downloaded a backup from iCloud from 2 days prior and now half contacts are missing and iOS and Mac won’t stay in sync.

I saw this post saying “big contact photos” can cause problems.

Any thoughts? Thanks - RP

The contact photos didn’t fix my issue. I had to do a nuke and pave and it’s been good ever since.