Thomas.Dahl , via OnePlus 7T , May 8, 2021 : Hallo, I am a HD1903 user and have ended up updating the OS to 11 and now regret it. The phone is doing some strange things like leaving apps floating around as little balloons on the screen when I move to another app and screen dimming is not going as low at night like before. This is keeping my wife awake. I have yet to find any features in the new OS that are enough to justify keeping it. How do I get back to the previous OS?