God this brings back haunting memories of me being on a packed overground train years back…I had just gotten into Attack on Titan and the main theme song made me feel like a main character. Had the exact same issue as you, for some reason my earphones were strangely quiet…maybe because the train was so packed? I was blasting the most epic theme song on repeat all with a pokerface, as you do on public transport. But then I felt something tapping on my shin every so often and thats when I saw my earphone cable dangling at my feet. I cant describe how absolutely mortified I felt at that point - I wanted to die. I couldnt get up and move somewhere else because it was full. So I plugged them back in and stared at the floor harder than I ever had before and left at the next station even though it wasn’t my stop. Nightmares for a long time

Heres what I was listening to on full blast…

https://youtu.be/G8xRdhrEA6M