I also just keep my fuel at default, and adjust according to the range ring on the world map. I just use the default 50% as a base, and add more if I need more range or use less fuel if I’m doing a short flight.
That’s why I’m not sure what fuel gauge problem you were referring to. Maybe it’s still there, but I use it differently than you do, so I never realise there is/was a fuel gauge problem.