It's not very clear if GSX doesn't work on JUST Flightbeam KSDO and the other FlyTampa sceneries, or it stopped to work *everywhere*
From your second part of the message, it seems that it works at Zurich so, it's not possible it would work at Zurich, but not at KSFO (since they are both airports that will work even if the product wasn't activated), so you should probably must see some kind of error message, like not finding the AFCAD data, or a similar one. Do you have such message ?