I don't know if this is already known or not, if it is sorry for duplicating, i haven't found nothing regarding this in the forum.

Another detail I noticed today is that the MSFS base path is different on Steam installations, with the directory structure being "Official\Steam" instead of "Official\OneStore" of the MS Store installations.

I also have a Steam install and have the same issue with airport names. Just for reference, the "Plan-G Files" directory in documents folder, after the MSFS2020 database creation, hosted 1,57Gb of data.

I attach the logfile.

My UserCfg.opt file is in %USERPROFILE%\AppData\Roaming\Microsoft Flight Simulator

Thank you for all your work!