Text Box Boundary Quirk

I read a thread at AUGI describing an issue where the Show Border option to create a box surrounding text fails to completely surround the text it contains. First, if you weren't aware of it, each Text type has a type parameter called Show Border.

The Show Border feature worked fine until I used the Underline override to put a line under the NOTES: heading. It also happens if I use any of the other overrides; Bold or Italic.

I created the following video to show what happened.

Seems easy enough to resolve, just use separate text for the heading. Unfortunately I found that Show Border fails to work properly if the text is altered later too. Just adding a new line to the text is enough to confuse the border/box. Sadly this means the concept of Show Border is fatally flawed...