Dishwasher drip tray (de)calcification?
Monthly vinegar use: a full cup in an empty washer on "pot-and-pans" mode with no heated dry.

This has kept my unit functioning well and lime/scale free since I tore it apart and discovered the pump, the "macerator", pretty much the whole lower works, plugged up with lime, scale, and a whole lot of solidified dishwashing soap. I predict that you will be disassembling the lower works, internet searches helped me tear mine down (along with trial and error and persistence) and put it back together.

I will never use bargain liquid or any type of granular soap again. I only use the gel pouches and it's been smooth sailing ever since.