Sound on if cover is closed

[Describe your problem, please try to provide as much information as possible]

I wil use my phone if they is in my pocket. The sound is then on my earplugs so I can hear the clues. However when I close the cover from the telephone the sound stops promptly. The solution is to keep open the cover but that’s not so good for the screen.
Is there a solution for this problem

(Debug information, this helps us helping you, you can remove this if you don’t want to share this data, it should not contain any personal or sensitive information)
Device: samsung - SM-S901B - Android: 13 - WebView: 113.0.5672.76
App-Version: 3.0.9 - 1062
Screen: 360 x 780 px - 3dppx

Please have a look in our documentation, it should work if it’s set up correctly: I can't hear any voice output / turn instructions [Kurviger Knowledgebase]