Whirlpool Duet Sport not working- Add a Gament light blinking

Hello:

I have a duet sport WFW8300SW02 which I am having problems with. During a wash cycle it made it to 2 minutes left and then stopped working. I started the cycle again and this time it made it to 9 minutes left. It would not spin out or drain. I unplugged it, drained it manually and opened the door manually to remove the clothes. When I plugged it back in and power up, it will lock the door and then do nothing. If I hit a button, the Add A Garment light will blink. I ran the diagnostics and am getting F26, F20 and F21. I did remove the MCU to take a look at the back of the board as I read in another post here and there is no blackend area or short that I can see. Does this sound like a door latch issue? Should I replace that? Or could it still be the MCU?

thanks for any help!