I am mixing a song now. And it just happened again. Right before the EQ changed on multiple tracks I had just adjusted a node on a volume envelope (like we all do all the time). I am not sure if that causes it or when I play through a particular section. Not sure if could be a "phantom mix recall", or "automation bug" that is now changing my EQs. Not pretty since I am trying to do final mix.
I will try setting a static automation on the High Freq on the channels that are affected anf see if that "holds" the EQ where I set it.