Testing out my TextField on Android has yielded an interesting result. While bringing up the soft keyboard and typing generally works, the backspace key and none of the number keys work. In regards to numbers these do not work when long-pressing a letter key to bring up a selection and selecting a number, neither do they work when switching to the number/symbol keypad.
I added in
System.out.println(evt.getKeyCode() + ":" + evt.getKeyChar()); to the KeyListener to see if there was any output and the listener is not called when any of the keys in question are pressed.
P.S. For the record most of the rarely used symbol keys don't work either, like the copyright symbol and degrees symbol, but who uses those in a game anyway?