Dishwasher won't drain

Hi,

I hope you can help.

Have a couple of inches of water at the bottom of the dishwasher.

Tried garbage disposal - it seems OK.

Run a couple of different cycles, I hear it is working. In the end, approx. the same amount of water still at the bottom.

Run a wash cycle, hit reset - didn’t drain

Got most of the water out (using a cup) - 1/4 inch left.
Run Rinse - heard water coming-in for 10-15 seconds, then it stopped - same 1/4 inch of water.

Run a wash cycle - water was running fine. Interrupted it with Reset 10 minutes later - approx. 2 inches of water again.

Any help? I am somewhat intimidated with opening the panel undernease of the dishwasher, but seems like this is where the problem and solution might be.

Thanks!
Ik