Mark get a Kill-a-Watt wall meter it will show you how much of a charge your getting.
They are about $20 at Walmart or Home Depot.
If your bike shows 0 battery left and you only charge up 9kW to full than something isn't right.
Your bike may not be set up for the 13kwh battery on the gauge but you may have that much range.
Yes, that is a great idea. My initial guess is that you aren't riding in a tuck position and aren't as light a rider as the tests were done with. Just riding upright at highway speeds could be the reason for your range. If you need to go far on the highway, make sure to tuck and lay so your chest is on the tank and you will see your highway range improve.
But to test exactly empty to full capacity, run the bike down to 88-90 volts resting, you can see this through the app. Then plug the Kill A watt into the wall, reset it, and plug in the charging cord. The next day see what the kWh number says. The actual capacity plus the charger losses should equal the nominal rating used by the battery industry. So for instance if it shows about 13 kWh that is probably 11.5 of battery and 1.5 of charger heat. But anything over 9.8 will prove it's not the 3 brick.
The other way would be with an IR camera like a FLIR. Run the bike hard on the highway, charge fast, and then repeat a few times, and check battery temp with the display and try to get it as close to 50C or 120F as possible and then view the bike from the side. If the battery looks uniform as a square, it is a 4 brick 13.0.
I'm 99.99% confident you have a 13.0, but try one of the things recommended and let us know what you find out. I will not rule out that humans could have made a mistake labeling the battery or programming something, I just find it highly unlikely. Remember also the bike will go for quite a long distance after 0%, although the bike will cut back power as the voltage sag tells the controller to limit power output. But I've gone almost 20 miles at slow speed after hitting 0%. It's nice to have a built in reserve so that if you are intending to charge somewhere, and get there, and something is wrong and have to go somewhere else, that at least you can get there going slowly. If the bike was able to use every bit of energy at 80 mph, I might use it all being to confident about charging, only to get there and the charge station is blocked or broken or in use. Meaning if it lets me use it going fast, I probably will. So unless you spend quite some time travelling slower, I doubt you used all the energy in the battery. What was the voltage of your last run to "empty"? I'll bet it was 98 volts or higher. But let us know.