My sound changed.

Hello, 

I'm playing Apex from that moment when game just came out (i think it was first week)

Few days ago my sound changed like.... Its impossible to play.

Before this I could hear my enemy around me, like I could hear someone behind me and next to me, but right now i can hear them only, if they are front of me. 

Even my teammates I just can't hear when they are pinging something or they are getting killed. Of course, If i'am looking at them then I can hear what they are doing, but from the moment when I torn my back to them its like silent, completely silent. 

What is the problem? I didn't change my headphones or other audio device. 

http://prntscr.com/p7g0e8

Thanks!