Captain reported GPS jamming on the ground at MMLO; Del Bajio International Airport; Leon/Guanajuato; MX.

Narrative

I have arrived to the aircraft for a flight from MMLO to ZZZ. I had begun my preflight procedures; and initialize the IRS (Internal Reference System); and while it was initializing; I had left the aircraft flight deck to begin my external preflight checks. When returning to the flight deck; I had noticed the GPS had not initialized and acquired a position; causing the IRS. To not find an accurate position I had notified the Captain of the issue; and we had monitored if the signal from the GPS would acquire shortly after we eventually received one. GPS position; however; would not acquire the second and subsequently after a few minutes; we had lost both GPS positions causing the GPS fault light to illuminate in the overhead panel. I had notified the Captain and the Captain had made appropriate logbook entries and notified the duty; Pilot; and Maintenance Control on how to further proceed we later try to receive an MEL to continue the flight however; dispatch had notified us that Mexico requires ADSB to be in Mexican airspace and the MEL would prevent the ADSB working correctly. We then waited for further instructions and if the Mexican controlling agency would allow us to continue the flight with this MEL and ADSB in operative. Dispatch had notified us that Houston center would allow us to proceed with the flight. However; we were still waiting on the Mexican; controlling agency to allow us to do the same contract. Maintenance in the airport had arrived and were diagnosing the issue and later in communication with the MC (Maintenance Control) Cleared the issue after receiving authorization from the Mexican controlling agency we were allowed to depart using a different clearance that did not require our RNAV capabilities the captain and I during our takeoff briefing had thoroughly reviewed the flight plan the clearance and are in route navigation planning and mitigating any threats that may occur from flying airway and VOR routing. Once we pushed back from the gate; we were normal operations till we were airborne and flew the departure SID MANTA3 which did not require RNAV capabilities and continued with our clearance using ground-based navigation equipment once closer to ZZZ airport. We were given an arrival into ZZZ airport that arrival procedure was an RNAV arrival however; in the notes it allows aircraft with DME/DME/IRU equipment to fly this arrival. we were given several delay vectors due to the weather in the area and had notified Center that we would be unable to take direct a specific fix unless we were on a course from a VOR to join the arrival course as we had some confusion with the arrival legality; because the notes stated we can fly this arrival if we had the equipment stated; however if we were off course; if this still applied and we opted for the safest option of intercepting the course from ZZZ VOR to the first fix and had notified Center of our intentions the flight from here till landing; except a go round; unrelated to the maintenance issue due to ATC separation was uneventful Cause: The GPS receiver; maintenance or what we had assumptions on GPS jamming in the area from previous company bulletins.Suggest: Stating clearly on RNAV arrivals; allowing DME/DME/IRU equipment if they are allowed to deviate from the course due to delay; vectors; or if constant vectors to final; after separation from the arrival procedure is required.