To everyone wondering why this is happening : it seems that almost everyone who has this glitch plays on old iOS devices, so It seems like Rili$oft made a very optimized and cheap version of the new PG3D update for older devices so that they can still play, i have an iPhone 4S and iOS 8.4.1 and i am facing the problems that you do as well, and thats not the only change here m8's
The Particles that appear when you shoot a player (the HIT and headshot marks) have been disabled as well, so there wont be as much lag, and deaths have been modfied, everytime you kill someone, they will always die in the original way (the soul flying away) the faliing ashes and the colory fading way's have been removed, so i you shoot someone with a Prototype, they will just die the same way that you'd kill them with s rifle that uses normal bullets.
These are the optimizations that i found so far, i hope this helps