I having an issue after the update on my samsung galaxy note 9 ( my camera goes black and says "you cannot use more than one application that uses camera at the same time camera will close does not turn on until I restart my phone) and I would like a permanent one. Please help
Sounds like a 3rd party app is using the camera. You could go into Settings -> Apps -> 3 dot menu -> Permission manager -> Camera and disable all 3rd party app use. You may want to first try changing them to "Allowed only while in use".