Before update to 20.3.1 I was able to set the position ans size of the Windows 10 taskbar. Using 3 monitors I would like to have the taskbar shown on only one monitor, which was possible before, but after software update, no longer. I cant find the "advanced option settings" for Eyefinity in 20.3.1. Have I gone blind?
Open an Online AMD Service Request (Official AMD Support) and asked them where they moved the Advanced Setup option in Eyefinity or Radeon Settings or if it has been removed from here: https://www.amd.com/en/support/contact-email-form
By the way, Found this 3DGuru thread where one of the Users mentions the same thing you are asking: AMD Radeon Adrenalin Edition 20.1.1 driver download
I have the same issue, it's been driving me nuts. HOWEVER, I found a solution. If you go to the path below:
C:\Program Files (x86)\AMD\CNext\CCCSlim
Then location the file "CCC.exe". Double-Click it.
This will launch the Advanced Settings you're looking for and from there you can set your taskbar to a single display. When I ran it, it automatically reset my taskbar the way I had it before the latest Radeon Software.
Hope this solves your problem!