So I've had this situation happen a few times, both to me, and watching it happen in front of me.

There are these very obviously AI airplanes that can get locked into a Target and shoot at a very low rpm yet hit accurately no matter the distance. I have had it happen to me multiple times ( and just happened to me again to prompt me to write this.) Some random airplane will get locked onto me, and stay locked on until I shoot it down. This last match I outrannit so far, I watched the icon disappear from the main map about 1 map grid away. Yet they were still able to single-shot snipe from that far away. Did not miss a single shot. There was nothing even remotely close to me.
It is incredibly frustrating. I hope it can be remedied soon.