Battery management not responding?

My GTD was taken for service, and a battery with only a partial charge (61Ah) was noted. I had also driven a longer trip before the service and typically drive 80km per day (2x40km). Now, I wanted to check with VCDS and accessed the battery management system, but after 20 seconds, it displays "Control unit does not respond." Furthermore, in the MSTG (Mechatronic Control Unit), under "Load Management," it shows "Inactive," which it should be active, as it's original equipment. Radio inside.
But why isn't the battery regulation responding?

Quote:

But why isn't the battery regulation responding?

Because it apparently isn't installed, or do you see a control unit with number 61?

I've had the radio on a few times in the fall while using the vacuum, and after about 10 minutes, it makes a "dong" sound and the display shows "low battery." I assumed that one was installed.

Battery monitoring is performed by the gateway (19)...