Having the same problem with the same aircraft. I am pretty unhappy about this, because it definitely limits the capabilities of the aircraft for no obvious reason. The problem is I do not really have one aircraft that fits all IFR-needs at the moment. I also use a Beech A36 and a TB10 for IFR-training. Here the problem is that the OBS-mode doesn't work well. And using the G1000 as generic ADF source in OBS-mode is just no realistic or practicable solution when following a flight plan or shooting an approach. Have you ever received an answer by laminar?