I have an iPhone 12 I use as a webcam on my Mac running Sequoia. I used it briefly as a webcam just to make sure it still worked after an upgrading to Sequoia. It worked fine. The 12 was still using ios 17 at the time.
Then I opened the iPhone Mirroring app to try it out. I found that it was already set up to work with the iPhone 12 which was still on ios 17, which I thought was surprising since I hadn't upgraded the phone yet.
But I don't want to use this phone for mirroring. I want to use my newer iPhone 15.
But I cannot get the mirroring software to switch to my 15. When I go to iPhone Mirroring -> Settings -> Reset iPhone access, I just get an error, "Unable to reset iPhone Access":
No matter what I do, it keeps asking to connect to the 12. I see no way to get it to forget the 12. Even after upgrading the iPhone 12 to 18, there seems to be no way to get my mac to stop asking to connect to the 12. And on the 12, I told it to forget the mac and that didn't help. Several reboots of my mac an iPhone didn't help either.
I also tried the solution here to no effect: https://www.reddit.com/r/MacOSBeta/comments/1f55455/potential_fix_for_iphone_mirroring_not_working_on/
Both phones are using ios 18.