I formatted my PC and did a clean installation of the W10. I installed MSFS 2020 (last version, 126.96.36.199), MSFS Navdata Beta (I upgraded to AIRAC 2103 REV 2) and LNM - Little Navmap 2.6.11 (last version). MSFS recognizes the installation of MSFS Navdata Beta because it appears in the content management of MSFS 2020. I exported the MSFS database to LNM, according to the user manual.
Everything was going well until I tried to make a LNM flight plan from SBAC (Aracati, state of Ceará) to SBFZ (Fortaleza, state of Ceará): LNM wrongly pointed out that SBAC was an airport in a very little city of Afuá in the state of Pará (a few hundred miles to west). There is no airport in Afuá but only an improvised runway without an ICAO code. In addition, the Aracati airport was plotted as ICAO SNAT code (which is a helipad in the city of Itaguaí, thousend miles away, in the state of Rio de Janeiro and is not even on the AIRAC base). Everything was obviously wrong.
To try to solve, using Navigraph FMS DataManager I updated the LNM AIRAC database but the LNM continued to place SBAC in the wrong location. To understand what was happening, I enabled the LNM to use only the Navgraph AIRAC 2103 REV 2 database for all resources (automatically disabling the information originated in the scenario database imported from MSFS), and voilá!, the LNM started to recognize the correct one SBAC location. I suppose the error comes from the MSFS database imported to LNM.
To confirm that, I did the same flight plan on MSFS 2020 which again plotted SBAC in the wrong location.
Trying to solve, I removed AIRAC 2103 rev 2 from MSFS with the help of MSFS Navdata Beta. I reinstalled AIRAC 2103 rev 2 on MSFS but the problem continued.
Than, I uninstalled the MSFS Navdata Beta, downloaded the app again from the Navgraph website and reinstalled the MSFS Navdata Beta. I updated MSFS again with AIRAC 2103 rev 2 but SBAC continued to be plotted in the wrong place.
the original AIRAC database of MSFS 2020 is wrong (SBAC and SNAT are in the wrong places);
Navgraph FMS Data Manager is successfully updating the AIRAC base of the LNM to cycle 2103 rev2 because, when the data imported from MSFS is disabled in the LNM, the LNM plots SBAC in the correct location;
And the worst, for some reason, it seems that the MSFS Navdata Beta is not effectively managing to load the AIRAC 2103 rev 2 cycle on MSFS 2020.