For a touch-screen application I have a window with 12 pictures. If a user taps one of the pictures, it is displayed much enlarged. The enlarged things is a container control that’s not visible.
In the IDE I have the (large) container frontmost, but when the app runs it shows up behind the smaller picture.
You can also use the menu item ad how and place all your Controls in your prefered order (easier to place TextField / TextArea and others in the prefered Tab order…)
It looks like a problem with the order of the controls when the app runs. Even if the container is set to the front in the IDE, something might be changing its position while the app is running. You could try checking its visibility and making sure it stays on top right after using ShowWithin.