PPlat flying exit row on a UA Express flight out of IAH on a CO bought ticket. Was not an issue of sitting in the seat, I was in it fine. However was told by a young FA that a new rule did not allow people using seat belt extenders to sit in exit rows. The older FA questioned the other FA and then apologized to me. Anyone hear of this new rule? I can imagine many people being upset with this if it is the case.