Kitchenaid kdtm 804 ebs1 Dishwasher Issue

Apparently this thing was a high end dishwasher when the previous owners of my house purchased it, somewhere around $2000 in 2016/2017.

The issue we're having is that water isn't coming out the spinning upper arm assembly, and I think it's only coming out of one of the three spinning arms at the bottom of the dishwasher. There doesn't seem to be a serviceable filter, so I think we've concluded (please help confirm) that it's one of the pumps. Which though? No codes, by the way, are showing up on the display.

Any help would be appreciated. Thank you.