Yes, unless something changed recently, you should be able to access the GUI. You can't do much via that GUI except look at signal levels though. Most of the features are only configurable via the Panoramic app. One of the many reasons I don't like the gateway.
Oh, so you live in a apartment? That is tricky because there is a lot of finger pointing between who pays for the wiring in the building but outside your apartment. You may also share your signal with other apartments in the building, which not only lowers your signal strength but allows for more ingress/back feeding from other people's connections.
I would check how the wiring is done for your building. Also, ask other residents around you to see if they are having problems too. I will know whether a wiring problem is to blame after seeing the signal levels.