Its probably your timer. Whatever cycle you use the most, is usually the first to wear out.
Here's a trick that's worked for me many times in the past.
Select the cycle that is having problems. When the washer should be running but is not, wiggle/move the timer knob up/down or left/right. If the motor kicks in or makes noises, it has bad contacts in the timer.
Just don't be too violent and snap off your knob.