Grinding humming noise Cuisinart digital air fryer toaster oven

I have a cuisninart model TOA-65 digital air fryer toaster oven that’s a little over a year old. It is now making a loud grinding/vibrating noise when it first starts cooking. It does it whether it’s toasting, convection cooking or air frying. If I bang on it lightly sometimes it will stop. It also stops on its own after it runs for a few minutes. I’ve taken the back off to see if there is anything loose inside that could be causing it. Didn’t see anything. I also tried to put a couple drops of oil on the fan shaft. Don’t know if I got the oil where it needed to go or not because didn’t seem to effect it at all.