I also have a second account for watching more technical videos and that leaks into my main account suggestions.
Poison YouTube recommendations at the nearest Starbucks! (Actually a marketing hack - encourage followers to log out and watch a channel's YouTube videos on public WiFi.)
YT algo is so messed up and it seems the more they try to shape the content people view, the easier it gets for bad actors to exploit the algo.
Shorts are the absolute worst for it and it's why I mostly stick to my subs page over the home page.
I turn this "feature" off every time I open it, it tells me it has saved that configuration, but that is not the case. like other poster commented, review your view history and delete anything you do not want to see or clear it out entirely. There is also option to "don't recommend channel" ([3x ...] beside the video)
This doesn't exist for search results, only for the feed