PS Vita Zer0 problem

Hi there.
Some time before I, playing Borderlands 2 (game is on cartridge BTW) on my good ol’ Vita, faced one big problem. When I play as Zer0 and use my active skill enemies instead of turning into a number-skinned silhouettes turn invisible just like me! Only some parts of them are still visible (like fur on bullymong limbs) but still black instead of bright blue. I even tried to delete my game files and re-upload them back but it didn’t work. Basically it ruins my whole experience as Zer0’s Decepti0n is a major part of his gameplay.
Is there any fix for this problem?