It could be that the keypad has gone bad. The charge button could be activating on its own.
Pressing charge while the robot is in the station makes it come out to mow. But, if it not within the mowing window, it will immediately drive back on the wire. You might also see it return early while mowing because the charge button will send the robot back to the charger.
Take a close look at the button. If it appears flattened, most likely that is the cause.
RobotLady