Lip piercing downsize irritation?

Hey, I got my lip pierced about a month ago at a 14g. It healed up fine and everything and I recently wanted a ring, so I went to the piercing place and they didn't have any rings in a 14g but they did have 16g CBRs. So I talked with them and figured, eh what the hell? If i wanted to go back up it would just be a minor stretch. So I've had the ring in for about a week now, and its a bit irritated on the inside, it stings a little bit at times and theres a little bit of a slit on the inside. I went back to the piercing place again to ask them what was up with it and they said that its normal for that to happen when downsizing like that. Is this really to be expected when I downsized from a 14g labret stud to a 16g cbr? Thanks!