The first task involving an AT gunner and him killing 30 ppl seems to be bugged:
When using a paratrooper squad to switch to the AT loadout and then using the 3 AT gunners to kill enemies (infantry or tankers) doesn’t count in the event progression. Yes I’ve used the ones with the AT symbol to kill ppl and it were a dozen of enemies so its not an observation issue.
Could be intentional but then I think it requires more clarification because they obviously were AT gunners.