Recon Specialist 2 bug
(Laser Designate targets that sustain 2,000 damage.) is not progressing at all.
Ideas
The wording could be A LOT better, the challenge requires damage dealt to vehicles that you have laser designated with weapons that require lock on. So mainly your MBT-LAW and MAS 148 on engineer i believe although Heli and Jet weapons count too, you're looking for the pop up "Guided assist" (or something along those lines).
Only damage done to vehicles that give you the "Guided assist" pop up count towards the challenge.
Hope this helps =)