*Where* it says is in Trial mode ? In the Addon Manager it will always say that, if you don't purchase it, but that doesn't mean it won't work at FSDT airports.
If, instead, you are saying you get a Trial mode MENU, suggesting to jump to a Trial airport, when you are in an FSDT airport, it's because there's another AFCAD active, instead of the FSDT one.
Check you haven't another AFCAD for the same airport at an higher level and be sure you haven't renamed any of the AFCAD that come with the FSDT sceneries, or you don't have two AFCADs for the same airport in the FSDT scenery folders.
