Don’t always assume the obvious or most expensive part is the answer. I jumped and ordered a new inlet valve and water level sensor. Did not correct problem. Started test cycle, opened door to check water level in bottom and water temperature - ok. Next I removed the water delivery tubes to the upper rack and checked for obstructions - none found. Took a step back and read some of the troubleshooting tips online at appliancepartpros.com. Tech support suggested that it may be low water pressure, and this led me to check the accumulator filter and the chopper assembly. The accumulator filter had a fair amount of scale buildup that I realized was mostly hardened detergent scale. I was able to clean the filter with hot water and a toothbrush. The real culprit was obvious when I opened the chopper assembly. The corroded chopper assembly fell out in pieces, and the chopper screen was totally blocked with food particles and scum. I replaced the chopper assembly and screen, following the online video, and ran test cycle with an upturned cup in upper rack. The detergent completely dissolved, and the cup in the upper rack was completely full of clean water. Finally, ran full load of dirty dishes and everything came out clean.