maytag dishwasher not getting water to top arm

[TIMBUHR]

The machine doesn’t get the top rack clean. all other racks come clean. I tested the top arm by putting a bowl in the top rack and and ran it for 20 seconds. the bowl had a little water in it. I did the same for the middle rack and the bowl filled over the top. i pulled apart the whole distribution assembly and there were no obstructions. the accumalator fine mesh screen seemed clogged. So I replaced the accumalaor altogether. now the top rack will spin if i don’t have the middle arms in. but, it won’t spin when they are in. it seems there’s not enough pressure. there are no leaks in the channel where the arms go in. There is enough water in the bottom. the water comes up to the lip of the tub and heater. The temp is 132 F. I changed detergent multiple times. I used a dish washer cleaner. I ran a field service test and there were no errors. I’m at a loss. could it be anything else besides the pump? and could i better diagnose and confirm before replacing. Thanks for your time