We bought our DW80f600UTS/AA dishwasher in about 2017 or so. In the last year it has started making a very loud screeching/squealing sound right at the end of the cycle. I could hear the circulation pump and discharge pumps working just fine with no sound, and if I put my hand over the vents at the bottom of the door the sound would change. I deduced that the sound was coming from the blower in the door. I took the blower out and found that the fan blades on one side had warped over time and were hitting the housing causing the sound. I ordered a new Samsung blower assembly and installed it. The total install time was about ten minutes. Now the fan is very quiet.
I have seen other photos of this same failure so I believe this is a design flaw. The blower blades are unsupported on the outer end, just cantilevered into space. It appears that over time a combination of hot air and the centripetal force from the blower spinning caused the blades to deform. Hopefully the new blades are a better design or material. If not, I expect to have to replace this assembly every 4 years or so.