Hi @vokinko1,
Greetings from the Roku Community!
Please be advised that you cannot simultaneously listen to audio on both headphone mode and soundbar using a Roku Ultra; the device only allows sound output through one audio source at a time, meaning you can use headphones or the soundbar simultaneously.
We hope you'll find this helpful info. Let us know if you still have any questions.
All the best,
John
John
Roku Community Moderator