I remember I had something similar. Motor stops like it is running out of fuel but fuel gauge still shows there is gas. This is not a bug, IIRC, this bush trip uses the XCub, which has separate gas selector (left and right). You need to keep an eye on the fuel levels on both wings. The xcub has nice transparent tubes to show the level on each wing. In the real world, you want to keep the fuel balanced switching the gas selector every 5 gallons:
Here is a picture of the transparent tube showing the gas level on the left wing (CTRL+5 on PC):
This is the selector (CTRL+6 on PC):
