It’s a FEATURE!

It is explained in detail in the section 1.1.1 of the user manual under the voice “TRIG”.
Basically if your TRIGGER channel is more or less in the CENTER of the standard PWM range, the sight and traces are disabled.
Check the actual travel range of the shooting (trigger) channel and set it up in order to get:
– 1.0mS (minimum standard PWM) when NOT shooting
– 2.0mS (max standard PWM) when shooting