I’m not sure if this is considered a bug or should be a feature request.
If the settings “Narrow document layout” and “Document border” are both turned off, and the setting “Show backlinks” is turned on, and you focus on a node with a backlink, the menu button for the focus node is barely visible (pushed off the document).
It can still be used with careful placement of the mouse. This is not a problem for me, but my mother’s hands are not as steady as mine.
I believe the document should become proportionally narrower when “Show backlinks” is turned on to allow room for the top node menu button.