I have it not installed, in fact have not flown since a very long time now, and I do not know the Steam version, but I heard and read repeatedly that the Steam version and the legacy default version of the game do not behave identically.
However I can try to help if it is an issue that is not typical for the Steam edition.
https://flyawaysimulation.com/news/4795/
https://flyawaysimulation.com/news/4939/
https://fsxinsider.com/installing-ad...steam-add-ons/
https://www.flightsim.com/vbfs/conte...-Steam-Edition
If you can still give back the game (less than 2 hours played), I woudl do that and instead find a new DVD to buy.