Difficult one to diagnose without being there to test with a multimeter and also listen to what is happening. Can be caused by a number of things. First thing to do is listen when it should be agitating. If the motor spins freely one way then sounds like it jams or sticks on the reverse swing then it is probably a clutch or brake problem down below. If it spins freely one way then silence then spins again etc it is an electrical problem which could be a timer fault or electronic forward/reverse module fault. You would need a multimeter & knowledge to find that fault.
Lincoln Appliance NZ
August 2017