We went to Puerto Rico (Cabo Rojo) for our honeymoon. It was great! I recommend it

Puerto Rico is a beautiful country.
Having said that, hubby (on an F1 visa OPT at that time) had no issues since there is no USCIS process point for flights going between mainland U.S. and Puerto Rico. He was never asked for his passport (nor was I) at any point. At the security gate we showed our MN drivers licenses.
We applied for AOS when we got home