The brake lines are sealed by a compression fitting.
The flared end usually doesn't get messed up. However the brass fitting that seals against it may be off slightly. It sounds like the SS line is the one that may be not correct. You can try smoothing out the flared end with some emry paper. Also look at the compression fitting and check it to make sure it's not scratched up. I had a MC that was like this......short of pulling the compression fitting out and redoing it.....not much I could do.