Thanks for the log.txt. I've got a fix for this that should address it in the 1.0.1 update (should release in the next few days, we are wrapping it up now). If it continues there, do let me know.
On the DA40NG operations, something to note with the fuel system is it is highly unique. I'd recommend checking out a DA40NG POH (there is one here) to learn more on the operations, but on this specifically, the fuel selector doesn't pick L/R/Off like most, it is Normal/Emergency/Off. For cooling a bunch of fuel is passed to the engine, and a majority is pumped back, through a line in the right tank, into the left tank. In Normal mode, fuel will pump from the left and the behavior is traditional. In Emergency mode, fuel will pump from the right, but the excess still goes into the left tank, causing fuel to inadvertently transfer. The preferred method of operation is to stay in normal mode, and then use the Fuel Transfer switch on the panel to get fuel from the right to the left tank when an imbalance is spotted.