New Armma Granite brushless 3s reverse issue

[foxinthecity]

Hello

I’ve recently bought the Granite. I’m experiencing intermittent reverse not working. I understand that you can’t just slam it into reverse and need to break (go to neutral) then reverse. But even after letting the car rest for 5 or 10 seconds the reverse just decides not to work at all. Other times it seems to work as expected. It’s ruining my enjoyment of the car. I doubt it’s anything damaged as the car has been doing this since it’s first run. Any suggestions what I can do (as a newbie) to try and fix the issue? Possibly a controller / connection to esc issue? Should I factory rest the esc? If so can you tell me how to do it. Or is there something else I can try? Plesse
Explain to me in non-technical terms as I new to the hobby, my first brushless. This Granite comes with the Spektrum controller. Thank you.

 

[Heisenburg]

Welcome to RC Talk. Can you recalibrate the throttle?

 

[foxinthecity]

Can you tell me how to do it. Or perhaps share a link to a YouTube video? and I’ll give it a go. Thank you.

 

[Doom!]

Recalibrate Throttle

 

[foxinthecity]

So since writing suddenly the car is now screeching and not moving. I see the piece running through the middle through if the car is struggling to spin :/ car is pretty much new. Very upsetting. I’ll take it to the Rc shop to see if they know what’s going on. Assume this is an issue beyond recalibration?