Kylo feels like he should be more active and the “miserable wreck” angle feels a little too played up. Force Awakens had the audience wondering who this person was, and I think it might work if the question is now “after killing Han and being beaten by Rey, what does he do?” Granted there’s potential in the scorned and pitied Ren gradually changing/evolving over the course of the film, but him appearing this, well, pathetic this early might be a bit of a turnoff to the audience.
Not helped by there being no real threatening hook with Hux or Snoke to really sell the threat of the First Order in significant fashion. It doesn’t have to be a typical “villains demonstrating how evil they are over the heroes” scene either, just something that really sets the tone for what the antagonists are in the rest of the film. Like in ESB, the scene with Vader sells the Empire’s scope with Star Destroyers/Executor, his intuition in finding the Rebels, and the subtle dismissal of lesser officers like Ozzel. From that you know the Empire is still dangerous, Vader obsessed with Skywalker, and get an idea of Darth’s place within the Imperial order.
This is just the opening, and there’s plenty of places to go from it, but for the first scene with the antagonists, Snoke laying out Ren’s failures and little else other than talk of more training just doesn’t seem like it grabs an audience all that much. Just my take, though.