AA lock-on missiles are ineffective

I don't understand what is wrong with the AA missiles in this game, including both the AA tank and the Engineer not-Stinger missile.

I lock on, the aircraft pops flares, I wait, after all the flares come out I wait another couple seconds until the flares disappear, then the lock on re-appears, I shoot and the missile starts going after the jet or aircraft then suddenly turns into the ground, and the reticule changes to miss. I know you are supposed to wait for after the flares come out, but it just doesn't work. The missile refuses to chase and makes a visible turn into the ground and crashes. Are the flares bugged and last longer than the graphical effect? This is really concerning because it makes it extremely easy to exploit by pilots and avoid missiles completely by exploiting this flawed missile behaviour.

Second balancing problem I noticed while piloting is that the flares recharge REALLY fast. I have seen this from the ground too, because many times a helicopter will pop flares again as soon as I reload and acquire the second lock on with the AA missile. It is incredibly disappointing and many players are giving up on equipping this gadget entirely because it is so ineffective!

Overall there are significant balancing issues with the dedicated AA options on the ground, the AA missile and AA tank are both extremely weak and likely bugged and not working as intended. Funnily enough, the TOW missile seems to be a much better option at countering aircraft because it doesn't suffer from this buggy behaviour that the lock on missiles exhibit, the IFV is better against aircraft than the Mobile AA tank! 

Please EA don't turn this into another BF3 or BF4 where aircraft were invincible from any threats on the ground. For comparison, in BF4 aircraft are essentially immune to lock on because not only they have ECM with uptime longer than its recharge (ECM took 7 seconds to recharge and last for 9 seconds, meaning that aircraft can have ECM more than 50% of the time on) but the lock on missiles used to be really weak, unable to even disable an aircraft IF you got lucky enough to hit one.

I can already observe matches in BF6 were helicopters have been totally untouchable from the ground because the AA weapons are so ineffective, players are actually discouraged from even attempting to target the enemy aircraft. There is a serious likelihood that players will give up on AA entirely if the gameplay does not reward players who try to fight against aircraft from the ground, resulting in even greater imbalance in favour of aircraft like the one seen in BF3 and BF4.