Found another commonality… disc rips regularly exhibit the issue (new Blu-ray or old DVD rips) - though still not 100% consistent; web rips do not.
Kinda makes sense for the Roku considering most web rips are same or close to what it has to playback from Netflix/Hulu/etc.
I also went a few days with no “live speaker” squelch noise… but did still experience a moment of silent audio not at start of files but when resuming from pause. Might be two different issues. More details about silence at resume silence at other post here: Starting after pausing has a 2-3 second audio silence on Roku
