This glitch should be fixed in Update 0.5.9.
Using your skill instead of this “indicator” would be a more reliable path to success. In many cases it does not trigger at all, in other cases it triggers in such blatantly wrong positions that it guarantees a miss (which can even be seen in the videos in the opening post). While it may appear to give positive results as an aim lead indicator initially, more thorough tests found that it triggers rather unreliably for accurate aim prediction. It is actually a remnant of old code back from Alpha that wasn’t intended to be left there – the icon “flashes” whenever the system thinks that the “distance to impact” point radically changes in a short time frame. Our developers are aware of this issue, thanks to player reports, and they were able to identify it already.
Wargaming has officially reacted to this issue, when Brynd, EU Community Manager, released the following: