I'm doing Duality once a week with some friends, and every time we get the weird bug after beating the final boss where we never teleport back into the main room. We're just stuck in the nightmare forever. Our gear is always back at the postmaster though. The "bug" with dying after hitting bells used to occur to us, but we just designated one person to always be the bell-ringer (shoot the bell) and it stopped occurring. I'm not arguing with your OP and telling you "not a big deal" - i'm just advising my experience and seeing if that helps others.