Air radar hard to lock-on, is it a bug

After this update I found my PD air radar being less capable of locking on enemies
1: they are harder to lock head-on targets in dogfight mode, even if they approach me with high speed
2: they are harder to maintain lock-on for head-on targets
3: the lock-on box is not exactly on aircraft-- even if at an altitude of 1000m above ground