Various screen sizes iPhone

With the following code I check the sizes of a device.

var deviceWidth as integer = min(self.size.height,self.size.width)
var deviceHeight as integer = max(self.size.height,self.size.width)

The screen resolution in points of my iPhone 12max is 428 x 926
When I start the app in portrait I get in the opening event 428 x 879, in landscape 428 x 926. I checked the sizes in the Activate and Resized event and I get various results.Resize in landscape gives 472 as Width, if I activate an 2nd screen I get 970 as Height in both portrait as landscape on all events.
What is happening here?