Mitochondria wroteusually just a bad connector/port. Do you have another pair you can confirm this with?
i have had 3 or 4 pairs of samsung earphone break and a older pair on Sennheiser break on me but i tested IPhone earphone not long ago and works fine
are you constantly putting them in/out on both devices?
no only use them like once a day always use my own earphone but use my moms earphone to test if its my headphone jack or earphones, i know my phone is in warranty worth getting it checked as so many earphone have broken
Back all your data up that you want/need and do a overnight warranty most places support that. They will overnight a new repair model, or you can do the normal 3-4 day wait depending on location. As you said, it is worth getting it checked.