"Yes my iPhone and Kids ones are old. But also my Mac Mini 4 on 26.7.1 and Wife's iPhone 17e still not working for this Asking for Kids Apple ID and password to start on their iPhones then sends us messages to approve Asking our Apple ID info and password and just keeps reasking. Yes Apple Apstore Aps. To buy new iPhones for little kids is not a good solution."
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Edit: "particularly those compatible with iOS27 and after"
Update ALL OF these Devices:
Being in a loop, update your device(iPhone or Mac) to the latest available updates. IMPORTANT: Be certain to crate a backup your device (iPhone or Mac), that way, you can have something to restore it from(iPhone or Mac), should anything go wrong during or afterwards.
Then, troubleshoot the transfer...
A. Change the Passcode:
You might eat the try changing the passcode. Go here: Change your Screen Time Passcode on an iPhone or iPad - Apple Support
B. Perform a Force Restart:
Go Here: Force Restart iPhone - Apple Support
C. Turn Off VPNs:
Have any VPNs turned on? If so, turn them off.