The AI can't use A2A weapons in the F4. It can't lock enemy air vehicles, will target(white box over target) but not lock( diamond around whitebox), and the only reason players can use it is because they are set with LOAL and autoseektarget, disable autoseek and LOAL then you can see neither player or AI can lock targets. The weapons work fine on other aircraft so the bug is in the F4 itself, and it's only A2A weapons, the Agm45 shrike will achieve lock, shown with diamond around white box, and AI can use it not a problem.