Are you sure you used 0000ffe0-0000-1000-8000-00805f9b34fb?
I have this service but it has no characteristics.
I also have two others for Generic Access and Generic Attribute but as the name implies I believe these are Generic (one contains the device name for example).
Maybe 0000ffe0-0000-1000-8000-00805f9b34fb is correct but the characteristics are not exposed until the device is switched into pass-through...?
Andrew