Checked some of the post require tinkering, afraid to tinker as it may end up broken. Will email where I got it to see any solution thank you

I recently received my first TRN BA5 from Aliexpress though encounter some problem, after listening 2-3 hr my right earphone ends up very low sound while my left is normal and after 4 hours playtime it's reverse side. Does anyone know what the problem as I recently started using wires for my phone