Police officers (For the most part, there are exceptions) are NOT lawyers, I have met many who thought they knew the law better than I only to find out I had actually read the book when either I pointed out the chapter and verse or defended myself against their charge. Plus one where.. Well, she took no action so there was not much I could do (she claimed my Driver's license was expired on a Saturday, My birthday was the following day (Date on license) and under Mi Law it was thus valid till Midnight the following Monday, I really wanted her to give me a ticket so I could deal with her in court but she declined).
My understanding is that if you are legal with the license you have in your home state, You are legal in all 50 States, DC, and a couple possessions. And at least parts of Canada and Mexico.
But you guessed it. IF you got a ticket, you need to contact an expert (lawyer) and if it turns out my understanding above is correct.. Bill the officer for your time and trouble, and his department as well. There is no excuse for him NOT knowing the law he enforces.