Communication between devices unstable in MacOS 26.6

Since updating to Mac OS 26.6 (and now 26.6.2) I’ve had increasing difficulty maintaining communication between my Mac and iPhone (which is also currently up to date). I can no longer consistently access the Messages app on my Mac, and iPhone Mirroring, which I’ve come to rely on for many things, often fails to find my phone. Most recently I’m getting an ‘unknown error’ when prompted to log in with my Apple ID (which has not changed in many years), and – perhaps related to all those problems – I’m seeing frequent prompts asking to share my Keychain ID with various system entities I am not familiar with. Given the increasing prevalence of various phishing traps lately, I’ve been hesitant to accept those requests, and will plan to screen capture them the next time they appear.

Is there likely a common thread between all these issues? Can anyone offer clues how to proceed, or do folks need to see those Keychain requests first?

My iPhone 14 Pro is up to date. Today I was struggling to text someone and kept getting an error. It was trying to text to the person’s landline, no matter what phone number I selected.

Cycling power on the phone to reboot it worked, so reboot may be a quick thing to try. Bugs!

Rebooting my Mac worked for now, but I think this is the 3rd time I’ve had to do this since I’ve been using v. 26.6 to be able to communicate with my phone. Never had to before. I’ll also keep my eyes open for those odd Keychain prompts and get an image of them.