My grill died.. I need a second opinion on fixing it

So this is a followup from my last post in /r/smoking where my grill died. The wedding went great, and I've still got a little pulled pork in the freezer I'm finishing off. I've been so busy with wrapping up graduate school and starting a new job that I've gone all summer without my smoker and I've finally had enough! I've had this Traeger since 2015. The time is coming where I'll spend money on a new smoker, but when I do I want to buy a good one and not go half way. Then I hope to sell this older one for more than it cost to fix.

So, here's a video of the grill a few minutes after being started. The firebox seems to have no problem lighting, the auger pushes pellets in fine and the auger fan runs whenever the auger is moving. The main fan on the bottom that feeds the firebox doesn't seem to have any problems spinning, however I can hear it speeding up and slowing down and it does NOT sound normal. It should just sound like a constant hollow jet engine hum, and instead it sounds like it's speeding up and slowing down.

1 minute video, the last 15 seconds you can clearly hear what I am describing: https://youtu.be/NX1NRviziqE

So my question is, the fan doesn't seem like it's gunked up, could the controller be the problem or is it probably bearings or something in the fan going bad? TYIA!