Yes, this issue has been reported and I understand Intel is currently developing new graphics drivers that are addressing Windows 10 issues. Once they become available they will be posted at: Intel® Download Center
Does the new driver fix this?
My external HDMI monitor won't fall into sleep but shows a black screen instead after inactivity timeout is reached in Windows 10. I didn't encounter this problem in Windows 7.
Thanks for the reply!
I realized that this only happens if I turn on the "Audio (no video)" setting, which my monitor probably doesn't support. So it is not a bug.
Louis, thank you for reporting this. I am glad to hear that you were able to resolve your issue.