One earpiece side of AKG earphone(which comes with the mobile phone Box given by Samsung for S8+) does not work properly. It works for sometime when I press the jack rubber coating part(that is the part where the headphone jack and wire are joined). My phone and earphone is 4 months old and it is in warranty. I use my earphones at home.
We apologize for the inconvenience caused. We would suggest you to visit nearby Samsung Service Centre so service engineer will examine your device physically and they will provide you the solution. Please find service centre details in the link provided http://www.samsung.com/in/support/servicelocation/