If you bought your coils from Pazon it is likely that they are PVL, which are about the best traditional style coils you can get. I bought some when I first got my bike on the road, looked identical to the pvl but weren’t and were cheaper. One failed after 300 miles. The both got replaced by PVLs and I never had another moments trouble, although the fault itself was had to track at the time. Like yours it would only happen at certain points.