Answer:
Please check to ensure that there are no mistakes in units in the model when entering the width t of the "Wall in Z". The entry must be in "mm" at this location in the program.
If the width t is specified in cm instead of mm, RF‑PUNCH Pro does not recognize the wall end or wall corner.
As soon as the entry has been corrected, the node can be selected again for the design in RF‑PUNCH Pro.