2018 Peterbilt bunk heater effecting the batteries strangely.

I have a 2018 pete. Im on home time right now. However my bunk heater works but the weird thing is that the battery for the bunk heater doesn't charge or doesn't uncharge it stays exactly where it's at. The auto start is on but it doesn't start the truck when the battery was almost dead. ( this was before it started acting weird) and now it doesn't charge or uncharge. so I left it on literally all day and night, never started and the battery didn't charge or uncharge for the bunk thermostat. When ingot into it today I took it for a short drive and came back and let it sit, my bunk lights were dead they wouldn't turn on until I started the truck. What could be the issue?