Product and version FileMaker Pro 14.0.4
However, see this post from 2012 which is evidently the same problem. Re: Extra line on report I cannot get rid of
OS and version Mac OS X 10.10.5
When setting either the top or the bottom border on the grand summary parts the opposite border is also set.
I am trying to set a bottom border on a leading grand summary and a top border on a trailing grand summary. The grand summary part (for both leading and trailing ) sets both top and bottom borders on the summary part.
How to replicate
Create a layout which includes a header, leading grand summary, body, trailing grand summary and footer. Set the border for top or bottom of the box to solid, 1px black - only set one, do not set both. You will see that the top and bottom borders are drawn with the border settings.
Workaround (if any)
Use a graphic object to achieve the desired effect.