Lpg electronic fuel sensor beeps mercilessly on Skoda

[Portuguy]

Even when the lpg gas tank is pretty full the warning beeper cuts in after 10 mins driving and continues its sound as if the tank is on reserve on our Skoda Octavia. The sound can be temporarily quietened by stopping the engine and starting the car again ,but later continues to beep .Where we live the lpg repair garages are few and far between . It also takes time for the sound to begin on a journey.