If you have an X Core controller that seems to be playing up then the most likely cause is that it needs resetting.
This can be done easily.
1. Press and hold the ‘PROG’ button.
2. While holding the ‘PROG’ button press the RESET button for 3 seconds, then release the RESET button while continuing to hold the ‘PROG’ button.
3. Continue holding ‘PROG’ button until time is displayed (this takes about 8 seconds)