ESC/RX beeping, steering but no throttle

[Ranger3113]

I'm new to the rc community and my first ecx is the AMP MT series, I recently had to replace my esc/rx, I'd turn it on then turn on my transmitter. The esc/rx makes 1 repetitive beep, there is power to the steering but the throttle will only respond when I play with the throttle trim dials.

Any ideas as to what the issue is and what I can do to fix it

 

[T7GGA]

this may or may not be of use ...

 

[weave]

Ranger3113, what radio are you using?