I don't really know what the exact mechanism is. It doesn't matter. It's a bit like driving a modern Merc. I know there's internal combustion at work, but I don't know what all the other stuff bolted onto the engine does. Nor do I need to know. I just need to handle the things that keeps it going, like put juice when its empty.
My point is fx will do what it wants to do for reasons that might not be apparent at first. Commen wisdom is you look at the fundamentals and then trade technically in that direction.
Well that doesn't work, becuase of technical moves like this, where the fundamentals are temporariliy inconsequencial.