My airship is inflated but sinks to the floor when I attach the flight deck and install the batteries. However, our airships will take more pressure than smaller balloons. That is why we recommend use of the inflation weights to determine if the balloon is full enough to fly. So, your airship probably does not have enough helium to provide the required lift. Note that the lift of your airship is very dependent on room temperature.
Cool temperatures require more helium warm temperatures require less helium.
It is best to inflate in the room you plan to fly in. In addition, altitude impacts lifting capability. Be sure that 9-volt battery is inserted correctly in the Flight Controller battery box. The red light on the Flight Controller will come on when any button or joystick is moved. If the red light does not come on, your battery may be out of juice or installed backwards.