Hi,
Can you check you have the latest Windows Updates installed? On Windows 10, the graphics drivers are being pushed out through Windows Update so it's worth checking.
It sounds like you have already done this but just to be sure please follow
these installation troubleshooting steps.
If you still are stumped please check if the affected monitor works OK when connected directly to the PC
Lastly please attach the output of
this tool when you reply
Thanks,
James