Many users faced difficulty with a Macbook Won’t Wake from Sleep since installing High Sierra. The typical troubleshooting steps of resetting SMC or VRAM could be a solution to issues with sleep and wake. Apparently Apple Support has told some users in this scenario to simply reinstall macOS via Recovery mode.
One workaround is to restart or shut down the Mac and then boot up again every time the Mac refuses to wake from sleep, but that’s obviously fairly annoying.
macOS High Sierra Won’t wake up from sleep Solution
Go to menu > System Preferences, then click Energy Saver. Set one of the following to fix the problem with MacBook going to sleep.
“Turn display off after” slider
“Display sleep” slider
“Computer sleep” slider
Check these setting which are causing macOS high Sierra going to sleep.
Also try these steps to overcome problem with sleep
Try these steps. These steps work for Mac Pro, iMac, Mac mini.
Turn off your mac.
Disconnect the facility.
Wait fifteen seconds.
Connect the facility.
Wait 5 seconds.
Turn on your Mac System.