Defender wiper problem

Hi, I have a 2014 Defender 110, last week in heavy rain the wipers stopped working. After a tow and a day of chasing the car, I stripped back the dash board and found the problem with the plastic drive gear in the motor, it was stripped in a couple of places. I replaced the gear and now the wipers only work on the fastest speed and don’t stop in the home position. I’ve replaced the wiper park switch, I still have the same problem. Wipers work fine on fastes speed but don’t park, they don’t work on any other settings.please has anyone come across this before?????