Uninstalled literally everything (including the game) and started from scratch. I can definitely say it's something Reunion (or Anxious Heart I suppose) is causing! I went through the scene with no mods (just the update and Aali's driver, the latter being installed indicates it's not the driver) and it proceeded properly. Once I installed Reunion, however, the glitch happened again (reloaded from the same save file). I don't know how to go about getting you a video, sorry. It seems like it glitches when Bugenhagen is supposed to say his next thing after the boogstar FMV. And I always install Reunion after Anxious Heart as you suggest (Reunion after other mods) if the order matters.
EDIT: And yes, adding that it always happens (with Reunion). I've tried different party members but I've attempted to go through the scene several times with Reunion, same issue. I think the only thing I haven't done is changed equipment and/or removed/changed materia.
PS - I didn't report it at the time cause it didn't break the game, was minor, and I thought it might be a memory fail on my part, but in hindsight it might somehow be related: I can't recall if the phrase "now" is supposed to come up during the junon march mini-game to signal when you should shoulder your rifle... if it is supposed to and I'm not just misremembering, though, it didn't. If that's supposed to come up, maybe it's somehow related to dialogue box cues? I'm no coder/programmer, so I just figured I'd throw that out there.