Unable to set 5120x1440 resolution in 22.04 LTS

I'm using Ubunt 22.04LTS with an Nvidia GTX 4090 and Odyssey G9. I've been using display port for a while with no issues but for other reasons have had to switch to using HDMI.

I've tried with both HDMI 2.0 and 2.1 and am unable to change the resolution higher than 3840x1080.

I've tried using every proprietary driver and have the same issue with each one. I've tried following a number of topics which describe resolving with xrandr but I get a number of errors. xrandr output:

xrandr: Failed to get size of gamma for output defaultScreen 0: minimum 3840 x 1080, current 3840 x 1080, maximum 3840 x 1080default connected primary 3840x1080+0+0 (0x527) normal (normal) 0mm x 0mm    Identifier: 0x526    Timestamp:  69529    Subpixel:   unknown    Clones:        CRTC:       0    CRTCs:      0    Transform:  1.000000 0.000000 0.000000                0.000000 1.000000 0.000000                0.000000 0.000000 1.000000               filter:     _MUTTER_PRESENTATION_OUTPUT: 0     non-desktop: 0         supported: 0, 1  3840x1080 (0x527) 360.806MHz *current        h: width  3840 start    0 end    0 total 3840 skew    0 clock  93.96KHz        v: height 1080 start    0 end    0 total 1080           clock  87.00Hz

I tried creating the resolution:

➜  ~ cvt 5120 1440 60                                        # 5120x1440 59.96 Hz (CVT) hsync: 89.52 kHz; pclk: 624.50 MHzModeline "5120x1440_60.00"  624.50  5120 5496 6048 6976  1440 1443 1453 1493 -hsync +vsync

Then adding it:

➜  ~ xrandr --newmode "5120x1440_60.00"  624.50  5120 5496 6048 6976  1440 1443 1453 1493 -hsync +vsyncxrandr: Failed to get size of gamma for output default

This does now show in the xrandr output but when I try to set it:

➜  ~ xrandr --output default --primary --mode 5120x1440_60.00xrandr: cannot find mode 5120x1440_60.00

But I believe the name is correct:

default connected primary 3840x1080+0+0 0mm x 0mm   3840x1080     87.00*   5120x1440_60.00 (0x531) 624.500MHz -HSync +VSync        h: width  5120 start 5496 end 6048 total 6976 skew    0 clock  89.52KHz        v: height 1440 start 1443 end 1453 total 1493           clock  59.96Hz

What's strange is the maximum resolution for Screen 0 in verbose output is 3840 x 1080. I'm at a loss on what to try next.

This is a dual boot and everything works fine on Windows.