I purchased this device as well as two more specifically because I needed to be able to stream video from my network drive.
Unfortunately, this is your problem. Roku has shown little to no interest in this use case over the years. It will probably get fixed... eventually, but it's never going to be a high priority in their eyes. I have yet to see this problem with my own videos and it's not clear why some do and some don't. I've been using ffmpeg and the same format for almost all of my MP4s for years - two audio tracks, one AAC and one AC-3, and they are both almost always re-encoded from the best audio track available. I've had problems just copying AC-3 tracks from the source as they won't always play, but that problem has existed long before the latest update.
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