Greeting @Jaymzbo,
Welcome to the Roku Community.
Enabling a feature on your Roku TV™ called Fast TV Start lets you wake your TV and perform various actions using voice commands. Have you checked if you have enabled this feature on your Roku TV? To confirm, use the instructions below:
- Press Home on your Roku TV remote
- Scroll and select Settings
- Select System
- Select Power
- Select Fast TV Start
- Highlight Enable 'Fast TV Start', and check the box to enable it
After this, test it first with your physical remote to see if it works then after your Roku mobile app.
You can visit this Support article to learn more: How to listen to music when the screen on your Roku TV is off
Does this clear up the issue you are seeing? Keep us posted.
Regards,
Nimfa