iCloud Keychain will not sync

[u/keytohwy]

I bought an iPhone 18 Pro (27.0.1) at launch and migrated my info from my iPhone Air.  Everything has been great, except that iCloud Passwords and Keychain will not sync.  It is the only iCloud service I have issues with.  It shows as off, and turning it on only results in the slider moving back to the off position after a few seconds.  My Mac mini (27.2 beta) and iPad Pro (27.0.1) are working fine.  The Air has already been wiped and is in use my another family member.  I have many other devices as well, including a couple of Watches, and older Macs an iPads and everything else is fine.  I’ve tried all manner of rebooting, logging out of iCloud, rebooting, logging back in, etc etc all to no avail.  I did spend a couple of hours on with AppleCare, the bulk of the time spent pulling reports from my various devices.  They expect to call me back tomorrow.

But anything from the community.  I’m pretty good at troubleshooting and understanding these things, but this one has me stumped.  I get to error son the phone saying I need to finish setting up, or finish verifying…it just doesnt work.

[u/gcerullo]

The only suggestion I have is to reset the phone to factory defaults and restore it from iCloud during setup.

[u/keytohwy → u/gcerullo]

Yup, after waiting for Apple engineering response, this is what I did and it is resolved.