Just looked at some images of the Earpods and the plug molding is definitely not bulky, so I doubt that's an issue. It could be that it extends ever so slightly farther (toward the tip), preventing it from going in far enough. You could compare it to another plug to see if there's a difference, but it might be so small you can't tell by eyeing it. After you check the port for lint, I'd suggest trying plugging it in then somewhat forcefully (being careful not to break anything, obviously; pinch the plug between your fingers and push that way, don't push straight on it from the end by the wire) pushing it in more to see if that makes a difference. Then trying gently angling/wiggling/spinning it to see if any particular orientation causes it to make better contact. If the "springs" in the port are too relaxed and/or the plug on the Earpods is slightly smaller than others (shouldn't be, since it's a standardized 3.5mm, but again, anything's possible, and I'm just throwing out ideas), then it might not be making good enough contact to work properly. This is where an extension or adapter would be nice, because it could help rule that out.