Mine was the i7-8750H, GTX 1060 one and the total same thing happened to me since the 1st day I'd bought the laptop. Sent it to repair under warranty for 4 times over the span of 3-4 months (they reinstalled Windows every time and replaced almost all the hardware, mobo twice, speaker, keyboard, wireless etc) but the problem is still there. Contacted ASUS (my country) they again asking me to send it to the service center. Even though I provided them screen shot of other users (4-5) on ROG forum, reddit and Amazon review of the same model saying they're facing the same hard freeze.
Tried all possible methods to solve it by myself (changing power options, DISM, sfc, DDU and reinstall nvidia, bought cooling pad, vacuum cooler for both vents, using driver booster, manually update all drivers (including hidden ones) ETC ETC ETC and nothing works AT ALL. I'm very sure the problem is with the ASUS laptop's software itself but ASUS is doing nothing to fix it or help at all.
I could not play games at all at this stage with the laptop and it's usage is just to browse the net and sits there as a decorative machine in my room....Could not refund either...
Went 6 days without freezing just by playing Subnautica but on the 7th day it froze twice corrupting my save file. I think It hard freeze more often with those high usage game like GTA V, kingdom come deliverance, PoE and even dota 2. Even when I left my game there to AFK and came back it froze, or with the game opened and alt-tab to browse, it also hard freezes. Could not play any games at all at this stage, in fear of losing progression and save files...
If anyone find a fix or solution to this non-stop random hard freeze please let me know...ASUS will not do anything at all even they are aware of this problem that's affecting this model and their users. They sold us a faulty NEW product and will not do anything to fix it....and we cannot do anything but to hold onto it and suffer.