I had a very similar experience on the Equinox March 2018. First leg of our B2B cruise, first evening of the cruise I wore shorts into the MDR (SD) (like I always do on the first evening). We were greeted and escorted to our table. As we were leaving the Maitre D discreetly asked to speak with us. He quietly advised me each evening going forward shorts would not be allowed in the MDR in the evening, IAW Celebrity's published dress code guidelines. No problem as I wouldn't think of wearing shorts and my wife wouldn't allow it. We all laughed about it. Second leg first evening I wore shorts into the MDR. As we were leaving the Maitre D spotted us and gave us two thumbs up and a have a great second cruise. I don't buy into the staff, especially the Maitre D is intimated by guests not following the simple published dress code.