Visio Pro 2021 – unglue perpendicular line

I have Visio Pro 2021.
I draw two lines and they are perpendicular to each other and they clicked.

question that i have is,

1. How do i unglue them as a separate line again, other than deleting and redrawing?
2. Once they are clicked, i want to grab the end point of one of the line, but i couldn’t. When i select it, it selected both lines and the adjustment i got is like a box instead.

Hope someone can help here.