Desktop not recognising monitor when connected to the built-in HDMI Port

Hi:

Just received my Framework Desktop that I completed the build. The Desktop was initially connected to an external monitor, keyboard and ether net using a USB-C dock. I was able to complete installation of Arch Linux using this configuration. However, now I decided to connect the external monitor (which has a HDMI 2.0 port) directly to the Desktop’s built-in HDMI port. But with this configuration, the Desktop would not recognize the display so would not boot even to the EFI firmware screen. Any idea how I can get this configuration to work, so I don’t need to use the dock with the Desktop in order to boot?

Thanks in advance for your help.

Jay