Why some discs make player vibrate loudly?

[bashfulstool]

Once in a while, a blu-ray disc will not spin smoothly (or whatever) and make my LG player vibrate loudly. It's happened repeatedly recently when I try to play SHOUT disc "Quatermass 2". I don't recall this happening when I first got the disc. It gets less loud if you chapter forward to the end of the movie, but is just as bad if you return to the start (and impossible to watch). I keep discs vertical on a bookshelf. The disc looks fairly flat, or as flat as the "Quatermass Pit" disc I got at the same time, which plays quietly.
The "Quatermass 2" initially wants to connect to the internet (I don't have a wifi player), but I wouldn't think that somehow created the issue. Should I try to exchange the disc with Shout?