301 gas gauge problem

Hello friends. I have 301 1.2 vti 13 model vehicles. After receiving gasoline, the indicator shows the correct. however, after a certain period of time, the gas level decreases and gives no gasoline warning.

My teacher is selling a separate kit for him, the price of 150-200 TL in LPG cleres comes together with 200-250 TL. The reason for this is that the gas gauge of our vehicles is falling according to the way we go, so if you do not drop it under half tank in my 206 vehicle, it automatically resets automatically at certain intervals.

ok thank you very much At first I was afraid lpg gasoline was burning at the same time, but thank god it wasn't.