ESC problem

Hi

I am just fitting the electrics into U177 - piston tanks functional, servos work, motors work ..... but a big but.

The motors seem only to function forward, I cannot get reverse to work. I am using Robbe Rookie 25 as recommended, I have followed the set up to the letter (noting the ability to disable reverse & not doing that step). The light is steady for forward & flashing when I pull it back for reverse as the manual says it should be

I am running the system on a Robbe FC-16 Navy with a twin stick controller on channel 1 & 2.

As forward is so smooth I must be missing something obvious - question is what.

Any suggestions would be gratefully received

ATB
Rob

PS I will get soem photos posted when it looks tidy.