The score says how it ended. xG says how it should have ended: it is the sum of the chances each shot was worth, not an opinion about the game.
A draw, but Bologna created more (3.01 xG against 1.84) — points dropped.
Bologna: −6.0 for the season (18 in the table). Sassuolo: −0.6 (10). The gap between points and xPTS is built from matches like this one.