I just purchased a Roku Ultra 4800. I have it connected to my Onkyo TX-NR676 receiver which is connected to a LG OLED 55C7P-U television. I’m experiencing shuttering or audio drop outs and can’t seem to get it to stop. Very frustrating.
Set it to passthrough mode: Settings/Audio/HDMI="Auto passthrough"
In (default) "Auto detect" mode it transcodes all audio to the highest detected Dolby level of the connected device.