Targeting help - disappearing circle.

[Blitzen]

I have a recurring problem;  After some updates my targeting help circle disappears from cockpit view ( i still get Rocket aiming help diamond when i tip the nose of the aircraft down a bit.) If I tip the nose far enough it re-appears just off the nose of the aircraft.It is also visible from the bombadier's position inside the plane & exterior view as well.Usually I can  get it back by uninstalling & installing game through steam utilities, but this time even that doesn't seem to work. Do I need to completely remove all of the folders( saving those I really ned) for BoS from steam/Apps/common before reinstalling as Steam uninstall only removes some of them/ Any help gratefully accepted.?