Biofilm buildup in dishwasher

Hello! I need some help. I have a Kitchenaid dishwasher, this one specifically:
Model: KDTM404KPS
https://www.kitchenaid.com/major-appliances/dishwashers/integrated-control/p.44-dba-dishwasher-in-printshield-finish-with-freeflex-third-rack.kdtm404kps.html

The biofilm buildup inside the dishwasher is driving me nuts and I can't figure out how to conclusively get rid of it.

A little background info:
-We have 4 kids, and run approximately 1.25 loads per day, so every few days we have to run 2 loads

-I know I'm not supposed to have to, but I do scrape and rinse the dishes, I just don't trust the dishwasher anymore

-I have used a variety of different detergents, from liquid to powder to tablets. I liked the cleaning power of the powder stuff the best, but too many bubbles would build up at the bottom of the pan and the dishwasher would stop mid-cycle. Even when using the lower end of the recommended amount casued this to happen. I can run a drain and it's fine, but it's annoying waking up to dirty dishes, so I switched back to a gel.

-When the dishwasher isn't running, I try to leave it open so it doesn't stay wet and humid. I have to close it when cooking so I don't constantly trip over it.

-Every month or so, I run it empty with a dishwasher cleaning tablet

-I also do a separate load with a bowl of vinegar facing up on HOT mode

-Every 6 months or so, I take the whole inside of the dishwasher apart and use a pressure washer to clean off the gunk buildup on all the parts. Then, I bring the pressure washer inside and literally clean out the entire inside, because it's so gross. I spray it down with a disinfectant cleaner, scrub what I can.

-6 months-1 year later, the gunk is back and it's thick pink, brown, orange. Each time it's a slightly different color.

What am I doing wrong or what else can I try? I don't remember this being a problem before, but I also didn't have 4 kids before. Is this expected?

Thanks for your help!