identityservicesd high cpu + Messages stops synching until I kill identifyservicesd

I submitted a bug report to Apple months ago, hoping it might get fixed in Sonoma or Sequoia, but alas the problem is still just as bad in Sequoia.

Bottom line, fan is always running, Identifyservicesd sucks CPU like crazy, Messages won't synch until I kill identityservicesd, it synchs then goes back to not synching.

Thoughts on how to identify the root cause?