I drive a 2000 Honda Accord, a 4 door sedan. The only explanation
that makes sense to me is what you describe, the bottom of hand brake
mount bottoming out and creating stress on the tongue just ahead of
the weld for the hard point.

In attempts to keep the tail of the trailer from dragging in every
service station, etc, some use a tow hitch which is too low. This
causes dragging of the tongue, which can do more damage.
Agnes Spindelberger is shipping a "lift kit" to me for a 1994
trailer. It will mount between the axle and the body of the trailer to
lift the lot 50mm / 2". I will then use a 2" higher trailer hitch, and
the whole trailer will have greater ground clearance.
Having owned another (1985) Cobra with a lift kit I found rigging
from the raised trailer, still connected to the car, is not a problem.
In that case the lift kit was a 2" square steel tube between axle and
trailer body.
The suggestion is NOT trying to resolve the problem of dragging the
trailer's tail by lowering the nose.
Jim