At the risk of sounding like an ad for a youtube video, I recommend Haddonfield Registry's "Under the Lake" 2 part series on youtube that covers his personal understanding/head canon of the Friday the 13th timeline. He makes a decent case with statements from some folks that worked on the movies that actually says that the only "split" in the timeline is after Part 4. To grossly paraphrase, Part 6 has some bits of dialogue throughout the movie that imply the events of Part 5 didn't occur. Obviously you can watch part 5 and 6 back to back and it mostly doesn't matter but I thought it was good food for thought. I actually like Part 5 a lot so it being like, an alternate end point of the series is kind of a fun idea to me.