LRP Sphere pulseing

[Si Coe]

Recently acquired an LRP Sphere TC off of someone on here, but trying it out today something is very odd.
It ran fine at first for around 5 mins, then the car received a very slight bump from hitting a flipped car (far from a major impact) and after that it started to be erratic. It would accelerate, then slow right down, then accelerate again. When I pulled the trigger forwards to stop the car, it kept going, very slowly, accelerating and braking on its own. As I'd been running for a while, I figured it could be heat, or low battery so pulled the car off and let it cool down.

Out again with the fresh pack, shoots of down the straight, powers out of first corner, and then back to this weird pulseing again.

So, I'm thinking is it the Sphere? Or the motor (which used to be erratic on the Orion I used before, which I thought might be the sensor wire and replaced, and which was never this bad) or even the radio gear? And if it is the Sphere - how do I get it fixed?