If the sound of your Soundcore Infini 2 cuts in and out when connected via HDMI (ARC), please try these steps:

1. Try a different HDMI cable.
2. Power it on, press and hold the source Input Button and Volume Up Button simultaneously for more than 8 seconds to reset it.
3. Test the Soundbar with a downloaded audio file.
4. Try connecting the Soundbar to a different device if possible.

If you still have any concerns or questions regarding this sound issue, please contact us and make sure to mention that you've tried the listed steps above for a quick and accurate solution.