Thanks for the video. That message is triggered by the internal tilt/angle sensor.
If I prop mine off the ground and at a steep angle, the drop sensor triggered message plays first, "Please check that my wheels are touching the ground”. If I cover the 4 drop sensors with foil, the “Please move me to a level surface” message plays instead.
So your drop sensors are probably working okay.
Try disconnecting the battery for a few minutes to force a full hardware reset. Let me know how that goes.