Part 107 UAS pilot reported they conducted a photo mission near a building and were approached by a public official. The pilot learned of nearby non-charted UAS prohibited areas they may possibly have entered.

Narrative

This morning; I was flying my Mavic 3 to take photos of a facility [in] Location A. I have a currently valid Wide-Area Authorization for ZZZ that would have permitted the flight; but I also filed for and received LAANC approval through the Aloft app for flight in the vicinity up to 400 ft. The only warning I received from Aloft was about the ZZZ Class B airspace. I was not aware of any airspace limits as a result of flying above the neighboring building to get shots of the target building.The flight started at approximately XA:51 am and I took a sequence of stills of the target building at 400 ft. and 250 ft. All operations were VLOS. At approximately XB:02; a marked US vehicle drove up and the Public Official asked me to speak with him. I asked him to wait a moment for me to land the drone. He then instructed me to turn off the drone. He asked if I saw the No Trespassing sign. He pointed to a small sign bordering the target site and a neighboring parking lot. I told him that I had only been on the target site's parking lot. He said that my drone however had been over the neighboring property and it was illegal to fly over the property. He took my drivers license and did whatever kind of check they do with a driver's license. He began writing about the incident. He said they were only collecting the information in case I did it again and then they'd be concerned about a course of conduct. I encouraged him to review all the shots I had taken to that point which he ultimately did. He was not concerned about any of the content of the stills. I also encouraged him to get my Part 107 license number since that's likely to be what others might want as a record.After he 'released' me; I resumed my flight at approximately XB:24 and there were no further encounters with the Public Official.When I completed the flight at approximately XB:49; I went back into the Aloft app to cancel the LAANC authorization. It appears that Aloft doesn't provide a process to cancel the authorization so it would have expired 3 hours after the flight started. I also noticed on the Aloft screen this time that there are 2 'U.S. Government NSUFR; Security Sensitive Airspace Restrictions that prohibits Drones from flying over designated national security sensitive facilities.' One location was 1.6 miles from the target site and the other was 2.6 miles. There was no mention of any issue with the site immediately adjacent to the target property.As of now; I still don't know that the neighboring building's airspace is in any way restricted other than a small no trespassing sign near the parking lot and the Public Official's assertion that it was restricted.I believe I did all the pre-flight planning (including airspace awareness) necessary for the flight and at this point I don't know of any rules that I violated. However; I'm filing this so that the airspace maps can be updated if indeed that airspace is restricted or the US Public Official can be advised that while I might not be permitted to walk onto their property; the airspace above the property is not restricted beyond being in Class B airspace.I would appreciate contact from NASA or the FAA to advice me if the space is restricted and how I might have known that based on current maps on Aloft and on FAA UAS Facility Maps.Thank you.