Before Insidious: The Red Door arrives and complicates things further, it is worth looking back on the Insidious franchise timeline so far. The Insidious movies have an unclear timeline. This is mainly because the original Insidious ends with the death of Lin Shaye’s Elise, but this character became the series' main character afterward. As such, later Insidious sequels jumped back and forth in time to fill in the details of Elise’s life before the original Insidious. Meanwhile, Insidious: Chapter Two picks up where the first film left off and finishes Elise's story after her early exit from the series.

https://screenrant.com/insidious-timeline-movies-recap-red-door-explained/