Can't pull down quick settings panel? So my HTC One M8 battery has been dying recently at around 30%. I'm pretty sure it's hardware, as it happens even after flashing a RUU multiple times.

Well anyway, I just searched for showtimes for a movie theater near me and it shut off with no warning, as now is normal. I plugged it in, turned it on and... Nothing from the Android OS is vibrating, as in the lower on screen buttons don't give haptic feedback like before, but all third party apps do, like my SwiftKey. I also noticed that I can't swipe down from notifications to get to my quick setting, it's like it was never designed to go any further. Another thing that changed is that Now On Tap is also disabled. Holding on the home key does nothing.

Is it possible the sudden shutdowns finally corrupted something? Should I restore the backup in thankfully made last night, or is there a way to fix any of this?
Don't know if you still need a fix for this (it's been a few months since you posted), but anyway I had the same issue with not being able to open quick settings and also my M8 stopped displaying notifications. Not sure what triggered all that, but after performing a few dirty wipe re-flashes of my ROM, I finally did a clean wipe (not just system and caches but also data partition) and that fixed it. Having a google cloud backup made downloading everything a little easier, but I couldn't have avoided essentially wiping everything but my SD card and needing to reinstall all my apps.