I finally found it in the Level 2 control panel, which I figured was irrelevant since I don't own level 2. However, I had the "Default Jetways are enabled" option selected, and all the default jetways disappeared. I then set it to "Default Jetways disabled by GSX" and they re-appeared, however I can't control them with CTRL-J. When I try to set it have to "Default Jetways are enabled" they disappear again.