Recently it's been showed to me that i probably made a false conclusion in my statement that it is ammo who is fault in this situation and in actuality it is a firing weapon. Which is supported by a fact that missile with IR sensor after firing from a vehicle would, as expected, fly to target even beyond objectViewDistance. I would make i wild guess that the problem lies in that the ammo config does not read fully and engine assumes defaults for objectViewDistance and viewDistance overrides.

In T163286#2304604, @pcc wrote:

Setting both objectDistanceLimitCoef and viewDistanceLimitCoef to -1 eliminated the issue me. AI combat performance with missiles also improved a lot.

Those distance limits on sensors penalizes players based on their distance settings.

Additionally tested laser weapons with setup written below. I will point out that i for now can't check test below on moving target.
AH-9 with DAGR and Scalpel + pilot with NATO Terminal under player control 1000m to Marshal sideways engine off. Remote Designator same side as AH-9 from Marshall but only 200m away from it. Result - While laser pointer in ObjectViewDistance missile can lock onto target, after distance to laser pointer become > ObjectViewDistance (by moving helicopter backwards) target is still locked, it looks like because of "track" in vehicle memory, after track timer expires lock is lost indicated by fully expanded and doted lock diamond, which eventually disappears. Interestingly if i will not move helicopter and only change ObjectviewDistance in video settings "track" part could continue for more than 10-15 seconds, don't know why.

Answering your question, KK. You can see airbourne targets in viewDistance while they in air, only when they land they start to obey objectViewDistance.
Also i would add to my NLAW test. I also changed other parametrs to be able to lock onto helicopters and planes in both visual sensor test and radar sensor test.
Additionally vanilla Titan AA MANPAD affected to this bug without any modifications. Planes affected if stripped of any sensor that can "datalink" to missile.
In conclusion most cases where this bug severly affects my community are in MANPADS use, both vanilla and modded.

It looks like only Ammo sensors are affected, but all of them. For that i tested modified NLAW in which i changed visual sensor to radar sensor.
But if sensor is a part of a vehicle no problems accured. Such type of sensor can also support other sensors of vehicle. To test this i used Gepard AA. With radar disabled it's titan missiles are affected by that bug. But if you enable vehicle radar, it now will lock target with it's sensor until you disable radar after which titan will track target for a 1-2 seconds while target's "track" is still in radar memory. As soon as "track" disappears Titan missile looses it's lock.