I had a similar issue the other day and I suspect they're related. I often load a .flp file into the map so the GPS is preprogrammed, but I've seen it not work on first load.
I have also seen the same happen in the 414 (and going back to the menu and reloading into the same plane fixes it) so I don't think it's TBM specific; it's either related to the fact that both have not been updated to use the WT avionics natively, with everything that comes with that, and rely on the marketplace pointer, or it's part of the regression that the WT stuff seems to have undergone with the recent SU.