OK. I noticed since the first post that is also happening with our Firetv stick 4k.
I believe that I know how to capture Plex server logs. And how to get the xml for the video. I followed these directions for that before - Captions no longer work - #16 by shark2k .
I don’t know about specific codecs or app logs if those are something different. Just running to make sure I get the right stuff… Thanks…