I'm either looking for an appliance repair person or plumber (not sure which) to fix a slow draining dishwasher problem. All the components seem to be working, and I can't find a blockage in the line or the disposer.

It's a Kenmore Elite (Whirlpool) dishwasher, touch panel controls, stainless steel interior.

All the cycles complete just fine - it leaves standing water in the bottom, and I have to run 3-4 'Cancel/Drain' cycles to empty it out.

So....the pump itself is working fine.

To me, that rules out a component issue.

There's no blockage in the disposer, and the high loop is in place.

I've run multiple baking soda / vinegar / hot water batches through the machine, but while that improves the situation, it still leaves standing water.

My main suspects at this point would be - a physical blockage in the line between the drain pump and the high loop - but unless there's a physical kink in the hose (there's not one under the sink), how would that happen? It didn't USED to happen, so something's changed.

It's possible it's not draining long enough, but that doesn't seem likely.

Since I've spent hours trying to resolve the problem, it's time to look for someone who knows what they're doing - but I'm not looking for someone who's just going to swap components hoping it's going to work (I've already done that - a lot). Is this a dishwasher problem......or a plumbing problem?