I've played through Act 10 completely on one character and I'm starting a second one. None of the cinematics have subtitles. I have the subtitle option enabled in my settings. I did play through on my first character with the KR font mod, but I disabled it so the game has no text/font mods at all, and there are still no subtitles.
Anyone else experience the same? Kind of unfortunate that there aren't any subs. Additional confirmations in the reddit: https://www.reddit.com/r/bladeandsoul/comments/c3cikx/act_10_subtitles/
As an example, this screenshot is during a cutscene where I think Mushin is speaking? I took the screenshot as the voice over was happening, no subtitles to be found.
https://i.imgur.com/Z1K4fsw.png
List of cutscenes with speaking parts and no subtitles (possibly incomplete)