My pc is also suffering from the CHIL8318 going missing after cold restart with both hwinfo64 and aida64. It's there after I install the driver (first picture), it's even there after a restart, but if I use shutdown and then restart it's not detected anymore. This happens in all 320 series drivers I tried sofar, currently at v326.84.
One of the more odd parts is hwinfo sensors displaying a blank were the CHIL should have been, just skipping some of the values, but also displaying some of them, like it did before in working state. (second picture) Not sure how it got the values there without the chil being detected?
I understand there's probably something outside the monitoring programs causing it, but just wanted to report the odd stuff and would be pleased if you look at it again. I did post in the aida and geforce forums too, to try and solve it, but no luck yet.