Hello @Kazaria, welcome back!
I tried to find anything to provide to you, but unfortunately was not able to find a lot, other than this reddit post that stands out.
It appears that the console has some limitations when it comes to Bluetooth.
Bluetooth sender devices treat Bluetooth connected devices differently dependent on the device type and Roam and Move should identify as speakers, meaning things like phone calls wont come through on the speaker.
It's likely that the Switch is looking for headphones rather than a speaker, and this difference in distinction can cause issues with the Bluetooth connection or audio playback.
A workaround could be to use a third party Bluetooth adapter connected to the USB-C port on the Switch. This could allow the connection without using the built in Bluetooth feature on the Switch, but would prevent you from charging while playing. Up to you if you are willing to try that out.
I hope that helps.
Thank you@ sotiris that’s unfortunate. I couldn’t find a way and endup using earbuds when in portable mode to play zelda :)