Problem started when we found water standing in the bottom. Searched through the threads and found that the check valve was the most likely issue.

I pulled the check valve and there was a little piece of loose plastic in there. Got it out and made sure the valve would open with a pencil, which it did. Reinstalled everything.

Tried to start everything back up and went downhill from there.
- When I press Wash, there is a couple of minutes where it does nothing at all.

- I then hear the motor but no water comes in.

- When I put water in myself, it seems to be sloshing away in there.

- But when I press the Cancel/Drain button, the water does not drain.

Any help would be most appreciated.

First check the sump area down to the bottom of the unit by disassembly and make sure you have no debris in it you'll need t15 and t20 bits for disassembly. Check the voltage to the inlet water valve where the hose comes in from the supply and make sure you have around 120v going to it.............then hit cancel drain and identify the drain pump and make sure you have 120v going to it as well and take a shopvac to the hose leading to your sink and suck any debris out also take the check valve out which the drain hose hooks up to at the unit and make sure you clean it out and make sure the rubber flap in it only turns in one direction leading water out of the unit only. If you don't have both motors getting the right voltage you either have a harness or a main control board issue most likely. Turn the breaker off let the unit sit for a little while maybe it'll reset. Also check behind the touchpad and unplug and replug the connections at the main board, inspect them very well for arcing or burn marks, check for moisture and damage etc etc......
Here's some pics on the sump disassemble
04-Pump and Motor Parts parts for Whirlpool DU943PWKB0 - AppliancePartsPros.com
Main board parts diagram
01-Frame and Console Parts parts for Whirlpool DU943PWKB0 - AppliancePartsPros.com

Any tips on getting that *%#$# drain cover off? The one that spins freely with the screw in the middle? Part #11 on that diagram?

It compresses with any wrench I put on it.

Well after all that I finally got everything apart. Thank you for the continued help.

Turns out that float was stuck. Once I got that moving freely the water comes in like its supposed to.

So the only problem I have left is that its not draining. The motor turns on, the valve opens freely, just no drain. I am currently running a cycle with two dishwasher tablets in there.

So since the motor runs, and the valve appears to be working, any other ideas about the drain?

Again, thank you very much for your help.

Very welcome glad you figured it out