Exiting lpg

I have been using my 301Allure 1.6 Vti automatic vehicle with BRC brand LPG for 6 years. I had maintenance yesterday. There was a constant water leak in maintenance and the master changed it. Now, when my vehicle is LPG at 2500-3000 rpm, when its foot pulls off the gas or brakes, it goes directly out of LPG to gasoline and then switches itself back to LPG. BRC service looked with the computer and says no problem. Engine master says we did not handle LPG. I would be glad if you could help.

There may be a problem with lpg gas cutters, teacher, would you have the cables checked?

Didn't check it in detail. He looked with the computer and said there was no problem and was sent. He said let's look at another time in detail. Thanks for your suggestion. I remind them to check the gas cutters.

Didn't check it in detail. He connected it to the computer and sent it saying that there is no problem. He called again to check detail. Thanks for your suggestion. I remind them to check the gas cutters when I go.