I have an Acer Predator G591 with Windows 10 V 1803 Build 17134. Sleep and hibernate functions work just fine when the laptop lid is not closed. It first sleeps and then, after the set time, hibernates.
However, if the lid is closed (it's set to sleep if it is) it never goes into hibernation from sleep. I have a Lenovo Yoga 720 as well that works just fine and hibernates as told.
I have searched for several months online and tried everything. It just doesn't do it. I've tried: hibernate on, off, Windows clean install, all the power plan settings... nothing seems to affect it. Any thoughts?