The only times in which the band would be unified and in sync were during musical matters such as songwriting and recording, but they wouldn't connect socially beyond the studio. You have two couples who are struggling with internal conflicts - John and Christine McVie had recently divorced, while Lindsey Buckingham and Stevie Nicks (who were only in the group for a few years by that point) were in an on/off relationship of their own - plus drummer Mick Fleetwood's then-wife Jenny having an affair behind his back.
In hindsight, it's really a miracle that Rumours didn't completely sink.
