I looked up "HVAC repair and troubleshooting". Got literally nothing but HVAC vids, with a smattering of vehicle AC vids and one home furnace vid. I clicked on a random HVAC vid to check the recommendations. About 75% were HVAC or AC repair vids. The rest were either music recording/mixing vids or DIY tool vids.
Then THIS showed up in the recommendations. I think the algorithm is trying to get me killed: