Good to hear (pun intended) - Roku made very poor decisions for its default settings for the 4800:
In order to promote their "new" Dolby Vision and Dolby Atmos capabilities they made "HDR Always on" the default which forces DV always on for supported systems, and then they made "Auto detect" (which should be named "Auto convert" or "Auto transcode") the default which forces DA always on for supported systems.
To be fair to Roku, all their competitors did/do the same with their devices with similar capabilities, and for the same braindead "lets market to the already sold!" reasons.
In the end it creates confusion, frustration, and issues for consumers who reasonably think something is wrong with their HT setup, not realizing in fact its poorly chosen default settings in their new device.
Changing the audio to pass through did not resolve for me. The issue with sound cutting out for a couple seconds still occurs. I've done everything I can think of to resolve. I've set to factory and reinstalled apps. I've then done system restart. I can't seem to get this issue resolved and Roku CS hasn't helped. Was just chatting with them and the guy disconnected me. Tried to reconnect and they are closed. Really don't know what to do at this point.