This started recently and appears to only happen in sim air battles (I only play sim and air assault modes)
I took a video of it but it’s hard to see on a flat screen, in VR, everything is in 3D until you die and you watch yourself crash, that is now a flat projection of the screen, but then it switches back into 3D to show you the enemy who shot you down.
In this video you can see the black border as I look up and around to show that it’s no longer in my world but a projection, just the killshot.
