Recreational / Hobbyist UAS pilot reported flying in controlled airspace without LAANC authorization under the assumption that unlocking the manufacturer geofence was sufficient. Law enforcement officers approached the pilot after the flight and questioned them.

Narrative

I am a FAA Part 107 Remote Pilot; with recurrent training appropriately completed within 24 months.On Day 0 at approximately XA:30am local time; I was flying my DJI Mavic Air 2 Quadcopter for recreational purposes under FAA Part 107 regulations.Prior to departure the following preflight actions were taken: Weather Check; NOTAM Check; Airspace Check; Landing Zone Check; Preflight Check; LAANC Authorization; Systems CheckThe UAS departed outside of restricted UAS airspace; and remained outside of restricted UAS airspace for the duration of the flight. Upon landing my UAS; I was greeted by homeland security; and provided immediately per their request in a cooperative manner: UAS Pilot Certificate; UAS Registration; Drivers LicenseThe officer took photos of those documents in addition; photos of: UAS Registration & Serial Numbers; Conspicuous labeling of operator contact info on the UAS; Conspicuous labeling of registration number on the UAS; My vehicle parked in a shaded area in the vicinity of the launch/landing zoneWhen the officer asked for a LAANC Authorization document; I advised him that the LAANC authorization was completed via the DJI app; and then provided the officer with a screen shot of the 6 digit verification code sent to my phone to unlock access to the area.When the officer advised that I was operating in restricted airspace; I pulled up the FAA UAS Facility map and showed them that I was positioned and remained outside of restricted airspace. I further mentioned that my particular UAS could not enter restricted airspace; because its software was up-to-date; and the geo-fencing feature would prevent such a violation. My UAS remained well below the maximum authorized UAS altitude rule of 400 feet for the duration of the flight.When the officer advised that I was not allowed to operate my UAS from my vehicle; I advised that they were incorrect. The vehicle was stationary; and that this was allowed.Sitting lower (vs standing higher) in this case improved my visual line of sight by many degrees. I explained that I was using the shade from my car to enhance the visibility of my monitor & to provide a stable platform to position my iPad in a fashion that would allow me to periodically glance at it and scan for the presence of any aircraft that might be in vicinity (well aware of the Class B arrivals; and helicopter tour traffic).I am not aware of any incursion or violation occurring. Both officers eased off after our interaction stating that they were only 'collecting information for the FAA'; and that no citations were being issued and that no enforcement action was being taken.This interaction uncovered that I did not have immediately accessible my recurrent training certificate. With everything happening so rapidly; there was not enough time to pull that document from my phone before they departed. One officer stated that I was much better prepared; organized; and compliant of the rules than most other operators that they have interacted with.I have since printed a copy of my recurrent training certificate so as to accompany my other documentation. I have completed this report as a best practice and for the sake of professionalism. I am open to any critique; recommendation; or corrective action you may have at this time.