Losing LOS to an ATG

[Jobu88]

This often happens with AT guns, especially if they're paired with an HQ that has a stealth modifier. The effect increases with the range to the nearest enemy, in my experience.

You can't target the gun directly when it drops out of LOS, but you can still use area fire directly on the nationality icon where you know the gun is located.

Once you get a unit close enough, they will maintain LOS, but again a gun in woods with an HQ that has a stealth modifier may require being as close as 20-30 meters.

I would guess that POS has a study of this phenomenon posted somewhere on the Blitz site.