Board Thread:Support Requests - Designing Your Wiki/@comment-36535642-20200426101537/@comment-9605025-20200427191927

It is because of how you are centering the image. When you use the "center" parameter of the file link syntax, it encloses the figure in a div tag. However, separate CSS applies a background color to all div tags inside a bubble notice. What you are seeing as "the border" is really the background of the div tag. Try adding this to the site CSS.