Season 5 of Agents of S.H.I.E.L.D. ended right before the end of Avengers: Infinity War, as evidenced by several references to Thanos' forces invading Earth and "the crazy stuff happening in New York". Season 6 picked up one year after the events in Season 5, which was clearly stated in the first episode. However, at the end of S6E9, Mack is talking to Daisy, who had been out on a deep space mission with Jemma since the end of Season 5, and asks her when he gets to hear the stories from deep space. She tells him he'll hear all about it in the debrief and makes a comment about seeing an ocean of lava and how she should have known better than to think she wouldn't come home to something more bizarre than that, to which Mack replies:
"Well, where you been the last five years... I'm looking forward to that debrief." (emphasis added)
Did I miss something here? Was she actually somehow gone five years since the end of Season 5, or was this a mistake by the writers?