I discovered that when I enter a vehicle, even when I exit it in the first-person VR, the camera will be stuck in the vehicle.
I tried to press V to cycle between the first-person and third-person cameras and when I returned to the first-person one, it returned to the vehicle view despite my character being outside any vehicle.
In case that matters, when I tried to launch the game as usual it crashed due to vorpX’s ScriptHookV being outdated, and so I installed the latest ScriptHookV.
GTA V game version: 1.0.2944.0