Please reset everything to default and let VorpX handle FOV and resolution. if you happen to have disabled auto settings, please re-enable that.
If you happen to have any mods installed (especially camera mods) try without. Some mods may affect the FOV.
If you happen to have the game installed under C:\Program Files or any other folder with restricted access, make sure your normal Windows user has write access to the game’s install folder.
Under normal circumstances the FOV is calculated precisely to match the FOV of your headset. Provided vorpX can actually set the FOV there isn’t really any margin for error in case of well known engines like the CryEngine. if you still want to experiment, you can apply a +/- 20° offset on the DirectVR page of the vorpX menu. That’s not necessary though. If you let vorpX do it’s thing, everything is set up correctly.