@UP_Hawxxeye The wildcat locks on decently faster than a stinger. That's normal, it's just how fast it locks. If you're trying to use the jammer mid-lock, I have a feeling DICE just really want you to not do that.
The lockon system is also not great and most likely suffers at least a bit from the netcode, e.g. I've seen that if you're getting locked, break sightline, then get locked again by the same person, they can fire a rocket without the lock showing up again on your screen. You just instantly get a rocket chasing you, as if it's the jet passive radar missiles, but it's not. Had this happen in ground vehicles too.