Huh. The only thing I can think of is a bug with h264 codec on your device or with how unity uses it. Unity doesn’t have its own h264 codec and just uses system provided codec. I don’t see anything different about that particular animation compared to all other ones and they are all encoded exactly the same way. Neither do I see any difference in how it’s used in script.
About 2 - game installs its assets and saves into public folder (which is why it needs file management permission), so you should be able to see it even without plugging into PC.