Kenmore Elite Dryer odd behavior

Got this dryer from a friend. He had problems with it. He says the timer stops mid cycle and he has to restart by pressing the start button and it goes again… Heats well and the timer moves. IT does not always stop at the same spot.
I pulled the thermistor and it read 11.6 ohms at room temp. I bought a new one and it read 13.1 at room temp the ohms reading decreases on both when it gets warmer.
What can I test ? is it a timer issues? or ad thermistor?? What do I check next and replace?