[Al Skierkiewicz]

Phoenix,
The wireless bridge must be wired to the specific gray connector on the Power Distribution Panel marked 12 volts. This is not the 12 volt battery but a specialized power supply internal to the PD. It supplies 12 volts even if the main battery should go down to 5 volts. What you describe is typical for the bridge when it is wired to one of the normal power outputs on the sides of the PD.
Also there are two antennas inside the bridge. If you look at the front of the bridge with the power connector and LAN connector facing the floor, one antenna is parallel to the bottom edge of the case on the left side and the second is parallel to the left side of the case in the middle. They are mounted about 1/4" inside the case. Yes, they are at right angles to each other. These two areas should be kept away from large pieces of metal and motors to insure good reception.
The small battery you are using cannot supply enough current to run your motors and provide more than 5 volts to the internal power supplies. When you are running a lot of motors or when you are trying to climb, the voltage will sag. When this happens the bridge, Crio and camera power supplies may shut down. If that occurs, the Crio will need to reboot and the bridge may not find the Crio as it boots. If you need to test with a better battery, motorcycles and personal water craft use this same size and capacity 12 volt battery. If you can get one cheap, I think you will find better performance until your First batteries arrive. Just remember you may only use the First batteries or the same type during competitions.