Is this an error in the nav…

… or should the blue bar symbolise an imaginary sky? Good morning first of all, I noticed yesterday for the first time this blue bar in the Navi. Meaningfully, it appears only in 3D display. I can’t remember having seen it before. I am thinking of a display error, which must be to search software side, because the screen otherwise works completely without error. The blue bar really only appears in the 3D display. For this theory, the fact that the beam appears sowhl in the large view as well as in the small representation to scale. Please do not fall over me, if it should actually be so. Thank you already. Greeting Max