This is probably the most trivial little bug ever spotted in BSS, but I just noticed that when the Navbar "Fluid" button is "off" (deselected) the word Fluid is highlighted in blue, which typically indicates a button has been selected. When you turn the Fluid button "on", the word Fluid turns gray (typically indicating the button is deselected.)
I know, totally trivial, but I did see, so I felt compelled to report it.