watchOS 10 in iOS 16
So, I have an iPhone X and recently got my dad's old Apple Watch series 4 (he upgraded to S9 and 15pro) but that watch is running watchOS 10 and is not pairing with my iPhone X. What should I do?
iPhone X, iOS 16
Question marked as
To use watchOS 10, your iPhone needs iOS 17. However, I believe you need at least an iPhone XS with iOS 17 to use with watchOS 10. See the 'Check your Apple Watch compatibility' section in:
Update your Apple Watch - Apple Support
Unfortunately, once you upgrade an Apple device, it cannot be downgraded (except for Berta versions).