I am using the latest Fire TV Stick 4K Max (Gen 2) , and quite often when jumping to last channel with a double tap of the pause button, the channel audio stutters and there is a video hiccup every 5 seconds or so. It does not happen nearly as frequently when I simply select a channel from the quick guide and change channels that way, although I have seen it happen. Usually to get things back to normal I have to exit to guide and select the channel again, and things are normal again.
If I turn off surround sound in Channels or change the Fire TV Stick Audio to 'PCM', the issue goes away, so it appears to be related to the Dolby Digital and Dolby Digital+ encoder on the fire TV stick (I believe they always transcode audio on these latest Fire TV Stick Max Gen 2's running Fire TV OS 8.1, even when not necessary).
I submitted logs a few hours ago from when this happened on the stable release as well as with the latest beta. Any ideas, or has anyone else experienced this with the latest Fire TV Stick 4K Max?