Clicking on popup “Fix project files associations” in EGS launcher solved it in all cases i’m encountered personally.
I’ve wrote a bit more details about it here: Generate project files button is missing - #4 by IrSoil
In the worst case you always can replace your *.uproject association with Engine/Binaries/Win64/UnrealEditor.exe for particular engine version, but fixing UnrealVersionSelector is usually better