Mine did the same thing and it was the motor. Mine was only 2-3 days old at the time. So my LHS was kind enough to just swap out the motor for a new one. Interestingly, the new ran better immediately. I mean, it was great before, but it drove like it had an upgraded motor in it. Same model was swapped. I’m wondering if I had a defective one from the start.
Anyway, the guy at the shop said it’s typical for these brushed motors to burn up real quick when you switch it to Lipo, which it did from day one. I’m prob a couple weeks away from going with a brushless motor.