Hi, if there is a topic that covers this please let me know. At STL the cargo apron does not allow for the 777, but since I live there in real life I know it does. (There are also 2 other gates that support the 747) So if there is a link that has this please let me know. If this is a possible fix please let me know. If not it is completely fine.
This is a know issue that has been caused by stricter gate restrictions in update 19.4. Some airports are already fixed but it all comes down to the endless volunteer work done by the airport editing team. They get to choose which airports to edit and update when they want so it is hard to say when KSTL will be fixed. But if you want you can see if you can convince one of the editors to reserve it and edit it for you!
Ok thanks for letting me know.
Covered in the Support FAQ.