Almost sounds like the driver is causing the computer to treat the monitor as an extended display instead of a primary. Have you tried connecting more than one display to check if maybe this is the case?
If you have a monitor and a tv connected to the same GPU card. When you boot up to Windows and the Monitor is black do you have video on the TV set?
If you have video on the tv set, go to Windows Settings - Display and make sure your Monitor is set as "Default" and not your TV Set. Also under "Display" check and try a lower Resolution for the Monitor and see if you get video. If by any chance Windows Resolution is set higher than the Monitor is capable of displaying it will be black. Just guessing at the moment.
Try a previous AMD Driver and see if you get video from the Monitor..
I have a HDMI Monitor and HDMI HD Television set connected via HDMI at the same time on my GPU card. Sometimes, when I have no video on my Monitor, I have video on the Television set .This allows me to go to Windows Settings to try and configure Display or uninstall whatever I believe is causing the issue. Just a thought.
Also check your Motherboard's BIOS setting to make sure your Integrated GPU is default and not set on PCIe unless you have a separate GPU card installed. If you have a separate GPU card installed, most of the time BIOS will automatically make that the Default GPU display.
Also you may want to double check the settings on the Monitor that is it set for the correct type of connection - HDMI , DP, DVI or VGA.
I connected monitor via vga while tv via hdmi and it worked. Then I played with primary/secondary monitor settings and now all works via hdmi as expected. Thanks for all suggestions.