Tbh I've noticed the same thing with cars and weird noises, half the time you just need the right cheap tool to stop guessing. Phantom draws are like that, you can't feel them out by unplugging stuff one by one forever.

Six hours of setup and a machine that gets things wrong more often is not the win you think it is. Your time has a price too, and if you spent six hours getting it running plus however long you waste fixing its mistakes, that $20 cloud plan starts looking cheap. Power bill going up $4 a month means you didn't escape the cost, you just moved it around and added slower answers on top. The big cloud models will keep getting better while your closet PC stays exactly as fast as it is today, so the gap only grows from here. Give it a few more weeks before you call it a keeper, because most people quietly switch back once the novelty wears off.