"I have a big and comfortable bath."
Translation:У меня большая и удобная ванна.
I think it's only when you're talking about parts of the body that everyone (or almost everyone) has - the normal and expected. Obviously, it cannot be assumed that everyone has a large and comfortable bath, so it's OK here. If it's any consolation, I also used есть and got it wrong. Will report it as an error.