Can you please provide more information about the issue you are experiencing? Is this happening on a specific channel or does it happen on all channels? In addition, does this happen when playing specific content or with all content?
With more information we will be able to assist you further.
I have a Roku Ultra. The voice is so distorted that must read captions. I have tried going to settings and restarting, etc. Still distorted voice.
If you have a 2020 Ultra (4800), try changing Settings/Audio/HDMI to "Auto passthrough" (do not leave it at "Auto detect")
Otherwise, turn off and completely unplug the power of all the devices in your HDMI chain (Roku, TV, AVR, etc) for several minutes, then turn them on, 1 by 1, in the following order: AVR (if you have one), TV, then Roku.