Since I was the victim of this issue because of my sound device, I will keep it to fixing the issue with audio device. But these steps can also be used for other devices like ethernet card etc. These may not all be the reasons in your case. You may try the solutions one by one and check if your problem is fixed.
Power Management using command line
Disable Cortana
Windows 10 have Cortana option that allows you to speak and Cortana will open it for you by listening what you speak. If the issue occurs after updating your Operating System to Windows 10, then it might be Cortana that is creating trouble and won’t let your system sleep.
Check Power Options for sleep option adjustment
The solutions are tested and verified. Hopefully, you will be able to disable audio stream which is creating an issue for a system while going to sleep mode. Thank you. Also see:
Fix: Computer Does Not Go To Sleep Mode In Windows 10How to Fix Unknown USB Device (Device Descriptor Request Failed)Fix: Laptop High Pitched Sound Problem Through The Speakers And Headphones4 Ways To Fix “Another App Is Controlling Your Sound At The Moment” Error In Windows 10How To Stop Your Computer From Waking Up Randomly From Sleep Mode
