I recently acquired a Dell U2720Q which supports HDMI, DisplayPort, and USB-C inputs.
My hopes was to use just USB-C to connect my laptop to the monitor and connect all of my peripherals to the monitor so it functions as a dock (power, peripherals, and display all over one USB-C connection).
However the monitor appeared to have a tiny resolution over the USB-C link and both X11 and Wayland refused to display to it. I ended up plugging in an additional HDMI cable and that drives it just fine at full resolution. X11 thinks I have three monitors, but I can disable the USB-C connected display. So this works but is sub-optimal to have two cables.
I’m running Pop!_OS 21.10 with all the latest updates. Has anyone had similar experiences?