It's a real surprise to me when I see a directional arrow, but then I'm a bit of a weirdo whose blood sugars meander within a fairly tight range, rather than change friskily.
When you say it isn't showing, do you mean that you feel your bloods are moving quickly, but the scanner isn't picking it up? If so, that could potentially be a timing thing, in that if you are feeling "off", testing and scanning at the same time, it's worth remembering that the Libre doesn't read blood but interstitial fluid, which is usually 10-15 minutes behind blood?