Are you sure GSX is really in Trial, meaning it works entirely, but only on 3 airports and on an FSDT airport ? That what Trial is.
Also, you said you saw a screen saying GSX is in Trial. Are you sure it's GSX and not, for example, the GSX L2 Trial ? GSX doesn't have a screen that says it's in Trial, it simply shows the 3 Trial airports on its menu, so you know it's in Trial. GSX L2, instead, has a proper screen saying it's in Trial.