After ranging a target with the range-finder, when you want to switch directly to the AT launcher i.e. scroll and select 'titan compact' for example, the binoculars get stuck in a jerking animation and you can't move either. It requires you to switch to your main weapon first.
This is a problem, meaning one can't quickly switch from RANGING -> LAUNCHING ROCKET. Instead they have to RANGE -> EQUIP PRIMARY WEAPON -> EQUIP LAUNCHER. Can lose valuable time this way.