Addressbooksync using excessive CPU time

On a regular basis the process Addressbooksync will use up to 99% of the CPU. I've searched for ways to fix the problem and most entries are many years old. I use Activity Monitor to stop the process several times a day.

I'm also having a problem with Contacts not syncing with iCloud. I don't know if the 2 problems are related. Apple Support has been looking into the two problems for a couple of weeks and have tried many possible solutions without success.

Any suggestions? I'm using a 2020 13" MacBook Air with Ventura 13.0.1