Same problem on my ultra (about 1.5 y.o.). Software is up to date. Most recently observed scenario occurs when pausing a show and it goes into screen saver mode. Strangely it went into Roku raining screensaver versus than the aquarium screen saver which is what it set to do. I haven't tried the audio settings toggle fix (but will next time), The hardware/software support 101 fix (restart) always seems to fix it. Daughter watches with subtitles on, but I don't know that I've observed any correlation to that. Please fix Roku peeps.
Same problem here on the ultra. Seems like after streaming for hours, the audio just goes sour. Reset works but problems recur over and over. BTW D/L 120 mbps... I shouldn’t have these problems Mr. Roku. Please advise your customers of a solution!
I am having same issue with both my Roku Ultras, one quite new one a bit older. After a few hours get garbled sound, have been unplugging power then plug back in to reset and it works again. Notice when use headphones on remote don't get the issue. Have set options to what recommended by Netflix further up (thanks), will see if that fixes issue.
As of 3/2/2020 I have been dealing with this problem for a week now. I did a system restart which corrected the issue but it came back 2 days later. Another system restart resolved it again and I left it off for a few days. I also emailed support.
My device is the ultra 4k device. The support response was excuse driven and lackluster. They blamed my hdmi cord, my tv, other devices connected (there are none) and the internet modem. When I explained all that I had tried (all but one thing on the list) they responded to try that one thing OR do a factory reset. I explained my disappointment in their reply and this product giving so much trouble when it's just over a year old. It's unacceptable. They said they thought my feelings were "unfortunate". I told them I would rather buy another apple tv device to replace this roku ultra than do a factory reset and have to re-install all my apps and then go in and type those emails and passwords again (it's a nightmare, you get it!)...
It's my opinion that there is something wrong that only they can fix and as suggested, maybe a software update would clear it. For me the issue just started a week ago so if there is a problem with the device itself, they should absolutely replace it. It could be a factory bug in the device if not a software problem that would be resolved with an update.
Either way, it's a huge disappointment as roku has by far been my favorite but it's not remotely that amazing that it's worth all this trouble.