Barry and Link
I guess I gave up to soon, it does work!
At a corner the reference lines must cross at the adjoining wall
and the connection is made. If I delete the wall on the left, the
connection is dropped.
Success!
David
AC 19-26 Windows 10 64 bit, Dell Prercision 7820, Xeon Silver 2414R ( 12 Cores), 64 GB Ram, Quadro RTX 4000 8GB