Went back and managed to recreate the bug, or at least I think it's a bug, and I attached a track file and will have a youtube link for actual video footage as well. Worth mentioning is that this is in single player too so there's not some desync stuff going on or anything like that. My theory is that the radar is actually losing track of the target briefly, but in this instance, it should then divert to having a simulated track. Instead, this never happens and the WCS never tells the missile to go pitbull at all. I tested this on the PG BVR instant action mission, but it's modified to have an AWACS so data link could potentially be a factor as well, but I genuinely have no idea. It's pretty easy to recreate because it'll happen pretty often if you crank more than 20 or so degrees in either direction. I also tested this in the newest open beta, this being version 2.5.6.60645.
Video file is linked below
https://youtu.be/pJYlZcNT0lI
AIM-54 bug.trk