In my app I have multiple view controllers, and most have a right-hand-side
UIBarButtonItem with direct “show” segue actions attached.
Having segued to another view and then pressed the
'< Back' button, the original button item remains faded out, although still otherwise usable.
This only appears to happen under iOS 11.2.
I can’t see any setting that could be doing this, and in at least one of the cases where this happens there’s no specific segue unwinding nor
viewDidAppear handling. I’d post some code, but AFAICS it’s all just default