Brake lights are not working after removing rear bumper

My Audi Q5 2013 was at a garage for a paint job and since then the brake lights are not working. The other lights are still working i.e. above the window, those in the rear bumper and above the license plate.

I haven’t scanned the car yet but it says Vehicle lights: malfunction.

The car was fine when I dropped it at the garage and the error was there when I picked it up. I know they took off some parts like the back and front bumpers but they told me that they didn’t touch the trunk lid.

Is there any wire or ground for the brake lights in the rear bumper?
Do you have to disconnect anything related to the brake lights when you take off the rear bumper?

Is it just a coincidence like they say? They don’t want to work on the car or cover the cost at another garage…