I've been using ubuntu (dual-boot) for a few weeks now and today the resolution went to 1024x768, with no way to change it.
I first tried the fix where you update the grub file to the resolution of the monitor, in my case 2640x1440. After updating grub and restarting, nothing changed.
Then I went to the 'software and updates' app and tried switching from the nouveau driver to the (proprietary,tested) Nvidia open kernel 520 driver. Then I restarted and nothing changed.
I'm on Ubuntu 22.04.1 LTS, with a 3060ti GPU
Here's some of the commands I ran, to give you more info:
:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 22.04.1 LTS
Release:    22.04
Codename:   jammy
:~$ uname -r
5.15.0-52-generic
:~$ xrandr -q
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1024 x 768, current 1024 x 768, maximum 1024 x 768
default connected primary 1024x768+0+0 0mm x 0mm
   1024x768      76.00*
:~$ lspci | grep VG
26:00.0 VGA compatible controller: NVIDIA Corporation GA104 [GeForce RTX 3060 Ti] (rev a1)
:~$ sudo lshw -c video
[sudo] password for (): 
  -display
       description: VGA compatible controller
       product: GA104 [GeForce RTX 3060 Ti]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:26:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
       configuration: driver=nvidia latency=0
       resources: irq:57 memory:f6000000-f6ffffff memory:e0000000-efffffff memory:f0000000-f1ffffff ioport:e000(size=128) memory:c0000-dffff
  -graphics
       product: EFI VGA
       physical id: 1
       logical name: /dev/fb0
       capabilities: fb
       configuration: depth=32 resolution=1024,768
I'm not very familiar with linux, so I'm not sure if I should try and follow the answer from this post, where the solution was to purge the driver,reinstall, and (i think) force the driver to work with the kernel?:
