Diagnosis
The projector's built-in acceleration sensor is detecting phantom movement, likely due to being placed on an unstable surface or a platform with subtle vibration.
How to Fix It
First, disable the auto-adjustment triggers. Go to Settings > Projection > Auto Keystone and set it to Off. Then go to Settings > Projection > Autofocus and set it to Off. Manually adjust focus and keystone once using the remote. Ensure the projector is on a completely rigid, level surface. A thick, solid shelf or a dedicated projector mount is required.
If That Didn't Work
Internal sensor failure is possible. Boot into the service menu to check sensor data. On the remote, press Menu, then enter 1968. Navigate to 'Accelerometer Test'. If values fluctuate while the unit is stationary, the sensor hardware is faulty.
Heads Up
Even with auto-features off, the projector will still run a full auto-adjustment cycle on every cold boot. This is by design and cannot be disabled.