No, the boundary wire is not recognised.

The wire is displayed plus/minus 1cm, even without a loop signal (Gardena allows you to switch off the loop signal when not mowing).
I localised my "breaking point" with an ohmmeter.
Fortunately, it was the T-connection for the loop return line to the base.
Check the plugs first

Bad. As the cable lies in the damp ground, it is not particularly accurate.
I have used an electric cable detector for this purpose. You connect this to the perimeter wire and follow the cable with the hand-held device until you find the break.
https://www.apfelkiste.ch/kabel-trac...

I think the cable will be detectable but not a cut.