TLJ did feel slightly disconnected to me the first few times I saw it in the theater, but after rewatching the whole saga in the few weeks before the TLJ blu-ray and then TLJ last night, it feels absolutely consistent. I think it’s a little difficult for me to get an accurate read on the tone of a movie like this until I can see it in isolation from theater audience reactions.
I think a big part of it must be the expectations thing. As evidenced by GothamKnight’s post, if you were expecting something after TFA and didn’t get exactly that, there might be a disconnect for you personally, even if in reality the two films actually fit very well together.