The chip is inert. No battery. But sensitive to temperature, and super sensitive to distance from the sensor ring.
In theory both keys should respond the same, although 1mm difference in location in the key would be enough to make that difference.
Remove the cowl, and check that the sensor ring is as far out towards the key as possible.
I physically touch the red section of the key (pic above) to the ignition barrel - so no problem with distance
