Volume Keys not changing audio

[usere9o0QVcQDO]

Ever since the update of One UI 5.1 my volume keys are not changing the audio levels consistently. 
There is a new icon that shows when hitting the volume keys. Does anyone know how to return the volume keys to their original functionality?

[AlexOOOO]

That icon looks like a volume control to a tv or monitor. are you using Good Lock Sound Assistant? Check in that menu to change volume control. It could also be a device in your Smart Things network that your phone is connected to.

[usere9o0QVcQDO · Accepted solution]

Found out what it is.

Spotify running in the background because of another phone we have running songs.
Cut the permissions for the spotify to run in the background and it went away.

[kevstones]

I too have this problem. Whilst watching You Tube the volume control now comes up with a phone icon at the bottom of the slider display and no longer controls the media volume. It's not Spotify as I don't have it on my tablet which is a Galaxy S9+. The software is up to date.