Why doesn't the head phone jack on my S5 Active work correctly?

[AC Question]

the head phone javk on my st active does not work correctly

I have had a s5 active for about half a year now. since I got it the head phone Jack does not work properly.I have checked for lint. I have found No blockage. Whenever I try to plug the headphones in it does not go completely in. Any answer to this problem would be immensely appreciated.