Games only render what player sees obviously to save resources. When you hack fov with vorpx it only hacks camera fov, doesnt tell game engine fov should be wider so game just doesnt render past its original fov. Maybe old game rendering pipeline is tied to camera so they react better when vorpx hacks it.
So you should always look for ways to increase games fov via other ways. For modern games usually there are few methods:
Setting files, especially for unreal engine games. Unreal games also have this https://framedsc.github.io/GeneralGuides/universal_ue4_consoleunlocker.htm to add console back (press ~ and type fov 120 after it hooks to a game)
And then there are specific fov mods for some games that people have coded, that dont just do it like vorpx, but make game fully aware fov is being increased. Generally I recommend searching games name in here https://www.pcgamingwiki.com or googling “gamename fov mod”
Wide fov and high res are 2 of the most important things to get right to enjoy games with vorpx.