In Windows 10 Tablet Mode, the active window is always maximized and other windows are hidden. If you Show() a window it will maximize and parent window will minimize.

In this gif we are trying to create a red 200px x 200px popup window. In tablet mode it maximizes and white parent window minimizes.

This is not a desired behavior for small popup windows. To fix it, disallow the window from maximizing: Set ResizeMode property to either NoResize or CanMinimize.

var myWindow = new MyWindow()
{
    ResizeMode = ResizeMode.NoResize,
}
myWindow.Show();

With this code, Tablet mode won’t maximize myWindow, and it won’t minimize the parent window.

This is a very rare issue, since most dialog boxes already don’t maximize. This issue happened to TouchVS extension because its WindowStyle = WindowStyle.None and it was never explicitly disallowed from maximizing.