Win 10 Pro, Unity 2019.2.17f1
This issue occurs on occasion, randomly. It has happened with multiple different scenes on this machine.
In this instance, I have a scene that is completely empty except for the default Main Camera and Directional Light. I have not added any scripts to the scene. In the inspector the camera is at position 0, 10, 0 with rotation 90, 0, 0 by default. Once I hit play, the camera instantly jumps to a seemingly random position and rotation. If I delete the main camera and make a new camera game object, the same thing happens to it. Please see this screen recording demonstrating the problem:
I'm thinking it might have something to do with the fact that I have SteamVR running on my machine. Does anyone know what causes this, and where I might be able to find a setting to toggle this behavior? Thank you
In the console you get
OpenVR Initilaized
You seem to have Virtual Reality Support enabled in the ProjectSettings -> Player -> XR Settings thus the camera position and orientation is controlled by a virtual reality device.
From the orientation I would guess that it lies around somewhere ^^
Simply disabling this should fix your issues.