Ubuntu 20.04 only detecting one out of three monitors with RX 7900XT

I recently built a new PC with three monitors and installed Windows, which worked without any issues. I then tried to install Ubuntu 20.04 and Ubuntu 22 in dualboot on a separate drive, but unfortunately, I only have one monitor working on Ubuntu, unlike Windows. My GPU is an RX 7900XT. When I run the xrandr command, I get the error message "Failed to get size of gamma for output default"

xrandr: Failed to get size of gamma for output default Screen 0:
minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080 default
connected primary 1920x1080+0+0 0mm x 0mm
    1920x1080     77.00*

and the output indicates that only one monitor is connected. I need help to resolve this issue, thanks in advance.

I found the solution

The problem was nomodeset I saw it when I ran the amdgpu-install command, it told me that nomodest was active.

Solution

1. In your terminal you type sudo gedit /etc/default/grub
2. You enter your your password
3. You find this line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
4. You change it this way GRUB_CMDLINE_LINUX_DEFAULT=""
5. You save your file and close it
6. In your terminal you type sudo update-grub2
7. You restart

I hope that if someone else has the same problem, it will help you

the solution comes from here