For related to iOS 17.5.1 update
My iPhone is not update showing unable to verify update
iPhone 11, iOS 14
Question marked as
Faheem1482 wrote:
My iPhone is not update showing unable to verify update
if there is an older version of iOS that was not installed on your phone.
Home Screen > Settings > General > iPhone Storage> very bottom of the list see if there are any old iOS update listings> Delete. Restart your iPhone and try again.
If your iPhone or iPad won't update - Apple Support