Hyundai I 10 Trend lpg

Hello together. I bought a new Hyundai i10 Trend lpg in April 2014. I have always had problems with the gas system since May 2014. It either doesn’t turn on at all or only after about 15 km. The dealer cannot find the error. Now a specialist from Hyundai Motor Germany should look at the car. Does any of you have any problems with it? The system is installed from factory. Thanks in advance.