House Stark (or: bastard and sister are in-fighting)
For now, we'll put Jon Snow in the category of "House Stark" until his true parentage is revealed to other characters in the show. We find Jon leading Winterfell in his usual way: a single focused gaze on his goal that often makes him blind to the feelings of those around him. Sansa has matured into a Southern Westeros political mind, and the contrast between the two styles of leadership causes immediate friction.
Jon values honor on an individual scale where Sansa would probably value winning over all else. This becomes clear when Jon receives a raven from King's Landing, telling him to bend the knee to new Queen Cersei, and Sansa, with a certain amount of reverence, describes how Cersei doesn't stop until she kills all of her enemies. Sansa says she's learned a "great deal" from the queen, and that Jon is too obsessed with the Night King (worth noting: everyone agrees on the name of this previously unseen uber-threat -- is it in the Westeros Encyclopedia Britannica?) to see her as a threat. Jon thinks "The north needs to band together, all the living north," and is sure the Lannisters won't march North now that winter has come.