In case you are suffering from the recent iOS update in the last few months, updates rending the calibration of gyroscope going all over the place.
Last week, Apple finally sent us an update to fix this issue, even though it was not mentioned in the update patch notes.
Once you update your iPhone to iOS 14.2, along with updating your VR apps.
Some apps have implemented the VR mode back with this update.
If you have noticed this issue, you could update your phone by enabling the update setting or just restart your phone to reset the gyroscope.