I was using the Kellerman Blue crosshair until version 9.16 of WoT.
In this version playing with arty with this crosshair messes up the whole game, the moment I press the "Shift" key.
So better disable the mod, because it's unstable.
I don't know how many of the other crosshairs have the same issue, I will play without a custom crosshair until it gets resolved.
Kind regards and thanks for the good work!