Diagonal lines – only downward

Hi,

just found another (minor) thingy. Couldn’t find any similar thread this time :)
In the attachment you can see a scheme representing the substructure I was talking about in my last post (one-to-many-to-one).

I’ve drawn it in a new layout I’ve created for a form.
You can see, from left to right, there are white lines going downward, and white lines going upward.
While the first ones remember their nature, if I close Tap Forms end re-open it again, I find the upward diagonals are back downward. It seems the only information stored in the line with the Origin is Width and Height, and they cannot have a negative value.
As result, I can’t save such scheme.

Thanks for your attention.