Fix for HDMI to an external monitor:

Run the commands below with the HDMI connected to my monitor:

• xrandr --listproviders (to make sure you have NVIDIA-G0 as a provider)
• xrandr --setprovideroutputsource NVIDIA-G0 modesetting 
• xrandr --auto

Ref: Found the info in the last post in this thread: https://www.linuxquestions.org/questions/debian-26/debian-11-bullseye-on-optimus-laptop-not-detecting-external-screen-4175690446/