Some games don’t allow mouse and gamepad to be used at the same time. Whenever vorpX has to emulate a mouse for head tracking in such a game, you will encounter issues like the ones you experience. You have three options two deal with such cases:
1. Play with keyboard/mouse input instead of using a gamepad
2. Play with your VR controllers in keyboard/mouse emulation mode.
3. Use the gamepad override (Input page of the vorpX menu) to emulate mouse and keyboard with your gamepad.
Both the VR controller mapping and the gamepad override are freely configurable.