Warning: This procedure will void your warranty!
You will need some solder skills
I had some problems with my headphone socket.
I often listen to music when I am working in the garden, so my phone is in my trouser pocket. My headphones have a straight pretty long plug and the stress on the socket during movement is higher than normal.
After a few month it started to randomly mute one side of my headphones. I reproduced the problem by moving the headphone plug in several directions. Could be like a faulty solder joint.
So I decided to open up the headphone module with a torx screwdriver.
Its a bit tricky but it doable. You have to lift up the metal tabs to open the module.
Here are two photos:
It doesn’t seem like a common problem but maybe someone has a similar issue. Its not to complicated!