I have an app that I built for iOS. I've upload my Asset file (2208x2208) to the assets in the properties of the Visual Studio AppBuilder extension. It created all the assets for iOS. I can see them right in the properties of Visual Studio. It created a bunch of portrait splash images and a bunch of landscape splash images.
My app is also locked for landscape orientation. I did that right in the General settings of the Visual Studio project. Set the "Supported Interface Orientation" to landscape. This is very important for our app to work.
The locking on landscape works well. However, the splash image is all messed up. For a split second it shows a horizontal splash image (literally, a split second). But, the image is stretched out. I know it is using one of the portrait images for that (because, with a little trial and error of setting different images within Visual Studio, I was able to determine which image it is showing). Then, after that split second, it flips the orientation to Portrait and shows the portrait image correctly (not stretched) for the splash screen (I also see the spinning icon, so I assume this is Telerik's setting this). Once it is finished loading, it takes the user to my welcome screen and flips the orientation back to horizontal.
This looks really weird. If the settings work like they should, I expect that it would load the splash screen completely horizontal through the whole loading process and that it would use one of my horizontal splash images the entire time. Even if it does the portrait image for the splash screen, I at least would not expect that really stretched out horizontal image for a split second before I see the portrait image.
Anyways, there is nothing really special about this app and how the splash works. I "think" this might be a bug in the Telerik product. But, I don't know for sure. Can someone please help me?
FYI - I am seeing this on my iPhone 6 when I do a real development deploy (i.e.: I am not in the simulator). Maybe it is phone specific, I don't really have any other devices to test with.