Maytag Front Load Washer will not fast spin and clothes still wet after cycle

Maytag MHW5100DW0 runs through the cycle fine but will not go into "High" or "Extra High" spin. When it does spin, it starts out normal (low), then steps up a little in speed (Medium fast) and spins at that speed for about 30 seconds then stops. After it stops, it attempts to spin the clothes 2 more times before ending the cycle leaving the clothes excessively wet. It's almost as if it is sensing an imbalance when there isn't one. I can't find any reference to an imbalance switch in the manual or online. This happens on all cycles that call for high or extra high spin and with or without a load of clothes in the washer. The drum is draining completely and the outflow filter was clean when I took it apart. Door lock light is illuminated and door is physically locked during the entire cycle.