Unable to set resolution for web client above 1920x1080 (ubuntu) in Nice DCV web client

I am able to get this working with web browser client connecting to Ubuntu 22.04 NICE DCV virtual session after editing /etc/dcv/dcv.conf and rebooting.

EC2 with NICE DCV created using CloudFormation template. Test with Intel (m6i.large) and Graviton(m4g.medium) instance types.

ubuntu@ip-172-31-30-156:~$ sudo cat /etc/dcv/dcv.conf | grep -B1 web-client-max-head-resolution
[display]
web-client-max-head-resolution=(3840,2160)

Web client was able to auto adjust resolution on my 4K display

In any case, I can manually set it as well

ubuntu@ip-172-31-30-156:~$ dcv list-sessions
Session: 'ubuntu' (owner:ubuntu type:virtual)
ubuntu@ip-172-31-30-156:~$ sudo dcv set-display-layout --session ubuntu 2560x1440+0+0

Edit:

Thanks for clarification; the above is for virtual session. You are using console (and not virtual) session on non-GPU instance.

As per Install XDummy driver for non-GPU instances, xorg.conf seems to limit resolution to 1920x1080 (virtual 1920 1080 ? ). Try changing the configuration.

Section "Monitor"
..
    Identifier "DummyMonitor"
    HorizSync   5.0 - 1000.0
    VertRefresh 5.0 - 200.0
    Modeline "1920x1080" 23.53 1920 1952 2040 2072 1080 1106 1108 1135
    Modeline "1600x900" 33.92 1600 1632 1760 1792 900 921 924 946
...
EndSection
Section "Screen"
    Identifier "DummyScreen"
    Device "DummyDevice"
    Monitor "DummyMonitor"
    DefaultDepth 24
    SubSection "Display"
        Viewport 0 0
        Depth 24
        Modes "1920x1080" "1600x900" "1440x900" "1366x768" "1280x800" "1024x768"
        virtual 1920 1080
    EndSubSection

I am not familiar with the xorg.conf syntax. You will need to test out your changes. Alternatively, consider using virtual session. The Ubuntu CloudFormation template from github may help