If you have a 12s assembly, then why is there a voltage on the lines above 12.The application should not show them at all! There’s 0.You should insulate the loose wires or cut them off. But it’s better to leave it, maybe you want to change the build to 13s or 14s later.
I use ANT BMS on my 14S - love it works great - but I recommend you only use it for charging/balancing the battery. When riding find a way to bypass the BMS entirely (I use a bolt/wing nut to quickly swap cables &bypass BMS). Why? Because BMS used MOSFETS to transmit power (just like the ESC) and therefore will overheat/fail just like an ESC unless it’s actively cooled.
The temperature sensors on the ANT - bms are already standing. And four sensors in the kit are installed on the body of the battery itself, two are installed on the contacts themselves + and - they heat up more.