Bootcamp: After rebooting from Windows 10, USB devices not working upon wakeup

Anyone have a problem similar to this one? Here are the simple steps.

OSX El Capitan. Bootcamp: Windows 10. iMac, 5k Retina.

Boot into Windows.

Reboot back to OS X using the Windows Bootcamp systray icon

After returning to OS X, allow your Mac to go into hard sleep

When you go to wake up the Mac, it won't wake via mouse movement or keyboard presses (both USB). However, hitting the power button will wake the Mac, only the USB devices are not working. The mouse (judging by the IR light) is not even powered.

a PRAM reset will always fix this problem. Once. Any time you return back from Windows 10, the problem is back.

Its really odd. I've seen issues close to this one, usually centered around having some odd USB device like a camera plugged in during the reboot. So I've made sure to have only the keyboard and mouse plugged in. Still the problem persists. I'm in the process of testing different combinations of keyboards and mice to see if, perhaps, one of the devices I am using is to blame.