Hello, oo explain the problem I give a short example. I created a new project in Swift language. Then I wrote only one line code in the viewDidLoad-method:
view.backgroundColor = .green
When I run the app on my iPhone6 device for the first time you see a green screen. As far as good. Then I change my code in
view.backgroundColor = .red
When I run it again instead of a red screen there is still the green screen. Any changes in my code are ignored (on a iOS simulator there is no problem!). I restarted Xcode again and also I did Cmd shift K but neither of them helped. I am grateful for any help.
(Xcode 11.0, iphone6 iOS 12.4.9, MacOS Majove 10.14.6)