u/Eldrina

We bought a new Whirlpool dishwasher about couple months ago. Runs well, dishes seem clean; but there’s this constant weird buildup of grease happening on the filter. I cleaned the filter; it came back.
I then expected choosing a regular hot wash cycle would deal with it (I chose Sanitary). The grease didn’t budge.

I use regular cascade liquid or Kirkland powder packets, and have not used rinse product. Do I have to buy RinseAid??? Is that the problem?? Is my water not hot enough? I ran the faucet until hot but result was same.

I don’t expect this with a new machine! My Samsung never had this problem.
What is going on??

How