I think you are experiencing an old bug. See if you have a folder "%LOCALAPPDATA%\Unreal Engine\Engine\Config" and in that folder a file called UserInput.ini. If so the game erroneously reads this file which probably has the setting "bEnableFOVScaling=False" in it.
You can delete or rename the whole folder "%LOCALAPPDATA%\Unreal Engine\" as no game should use it. Rename it to "Unreal Engine (old)" or something.
I've done like this so I can easily find back to it when I need to test like now
Note the space in "Unreal Engine", you might have another unrelated folder called "UnrealEngine", don't touch this one!