Thank you all for the replies!
For now I download an app called “All black” which give me an…… all black screen when playing Apple Music on the AppleTV.
@Carolpa, If you use your Oppo BR player with audio only, I guess it would still turn on the tv right? although you might get a blank screen, tv is turned on….thats my point. It would help if we could mark the HDMI input as Audio only in the Theatre settings to avoid this.