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.
Ensure you're equipped with rifle, AT launcher and rangefinders.
I have had this like 3 times, but not related to switching to the launcher, I have had it when switching to primary as well since I hardly play with AT and still get it, unfortunately I cannot give exact repro steps as it usually happens on a time when I do not pay too much attention the combinations I press, and it's during stressful situations. trying to reproduce on my own leisure, I have not had success yet, but this problem does exist and is a pain. much like the stuck running anim, pressing v resolves it at that point of time.