It seems to be an older thread and I can't reply.
I am having the same problem as https://community.roku.com/t5/Discussions/Roku-Ultra-Volume-glitch-after-some-time-Volume-glitched-h...
I can see the user reports it was not solved. I have this problem on both of my Roku ultras on an LG TV with earc soundbar and a Samsung TV using the built in speakers and in various apps - Netflix, Hulu, peacock, max, etc.
So it's not the TV, it's not the app, the Rokus are rebooted and fully updated.
Unfortunately as this other poster wrote it is random - it might happen after a few minutes it might not happen at all it might happen after watching for a few hours. The only fix I've found is to hit back to stop whatever is playing and resume it.
I had a thought last night while trying to Google this problem and not finding much other than the post above. Could it be a bug in the Roku sound leveling feature? I absolutely have that turned on both my TV's because I feel like everything is practically unwatchable without it.
I will try watching with it off to see if it repeats but again unfortunately it is not intentionally repeatable. I was wondering if anyone else has thought about this or if Roku can consider reviewing the sound leveling function for problems?
edit: fixed typo
fwiw I just replaced my ancient I have no idea what version HDMI cables with name brand new ones. I will report back if this made a difference.
I've never had this problem with any other apps. Just the DirectTV. When I need to leave sound on for my animals while gone, I have to exit DirectTV and switch to Pluto or something other then so this doesn't happen while I'm gone and affect others in my building.
I am having the same issue with a new HDMI cable and a Roku ultra. As @Cheetah15 has previously mentioned, it seems to only happen with the DirectTv streaming app as I am not sure I have noticed it with any other app. We are not using sound leveling as I thought this was the issue initially, but I have come to find out from my research there are others experiencing this problem as well. To fix it, I usually will either flip the channels or hit the fast forward or rewind button and it comes back to normal levels. AT&T needs to fix their app IMO.
yea new HDMI cable did not do anything. we for sure see it in Hulu, max, Apple TV, and I think prime TV.