I recently send in a ticket on it and the only reaction was "known problem".
Sometimes it does not work, sometimes it does not work perfect.
To get the highest chance on success, open the largest of the two routes and try to merge the smaller route into it.
Even if it looks successful, check the corners of each baseboard. You will notice that 1 or 2 squares lost their texture and that 1 or 2 squares have been lowered to 0m height.