Did you changed a setting on your transmitter? can you try another receiver/transmitter? i had an issue simular to yours (a different BL setup) but had the same problems. I can be the transmitter.
I got this answer from Charlie at Novak and now it works perfect.
Oh, this is easy.
Turn on the truck and the Transmitter. Put the Truck in the air, wheels off the ground.
Then “flick” the trigger a few times and look at the LED on the Esc.
You’ll likely notice that when you return to neutral, it is not turning Red. This is because your Trigger Pot is wearing, and not returning to the exactly the same neutral point every time.
The ESC is “required” to see neutral before the reverse engages. So if you move your throttle trim on the radio until you get the solid red light at neutral, it should start working again fine.
Is there a setting on the ESC where you can widen the neutral range? Short of replacing the throttle pot (or the whole radio), this would be the easiest solution.
If it IS a neutral range issue on the radio, you could play with the throttle trim until it does work. I'm sure the ESC has a range where it will register neutral so it should be fairly easy to find a good spot that works.
My Laser 6 has a fairly wide neutral range, but occasionally the motor doesnt want to reverse- tempermental (must be female). A quick flick forwards then back and it works again.... electronics eh?....