Hi Chrissy, a cycle with unexpected changes in what had previously been consistent, reliable behavior of the attacks, such as the time of day they strike, duration, how many attacks per day, etc., is a phenomenon I've seen reported aplenty, and I've experienced this myself.
Just when a pattern has been seemingly cemented into place, stuff will suddenly out of nowhere get all switched up.
Long remissions after many years with CH is common enough too. Many get caught off guard when the CH does return following an extended remission, having believed their CH had completely burnt out.