Hello ​@Conzo123, welcome to the Sonos Community!

I’m sorry to hear you are experiencing audio quality issues with your Sonos Arc Ultra while playing Dolby Atmos content on the Xbox Series X with the night mode on.

I’ll ask you a few questions, just to understand the issue better:

Does the audio distortion occur when you are using the TV applications instead of the Xbox’s?

Does it still happen if you de-activate the night mode?

Does the Sonos App show the label Dolby Atmos when the content is playing on your TV on the “Now Playing" screen?

Feel free to reply here with the answers, but I would recommend to also reach out to our Support Team for some live troubleshooting. Make sure to Submit Diagnostics within 10 minutes of the distortion happening before reaching out.