Trailer unit malfunction after short circuit in installation

Few days ago I was changing electrical socket at the trailer (for a boat, detachable rear part). Due to inadequately tightened screw short circuit happened in stop lamps circuit. It has happened to me once before, at that time fuse was blown so it was easy repair. To my surprise consequences are the following:

• no voltage at the pin for the stop lamps at the car (checked with the trailer installation checker)

• no fuse blown

• message 'ACC disabled' when trailer installation is hooked (happens even when fully functional installation is attached)

I checked the fuses (no 22, 28, 38 are for the trailer) and they are not blown. Scan from the VCDS is attached.

Any suggestions? I have already booked service with Skoda steelership, what I am afraid that their suggestion wound be changing complete whole trailer electronic unit.

Log-TMBJJ7NE6K0146212.txt