i found the UFW site and the only thing i can find there about the G550 is some blog post... they do have numerous craft and custom airports that xsaint has done but all of the links are broken...
to even begin starting to troubleshoot this/these craft, the log output of FG is needed when loading up with the craft in question...
it would be a good thing to also tell us which FG version you are trying to use... full version number, please...