External monitor only works with specific resolutions: Ubuntu 20.04 and Dell XPS 15 7590

I installed Ubuntu 20.04 on a Dell XPS 15 7590 (2019 model). While an external 2560x1440 monitor was working fine while Windows 10 was installed, the screen doesn't detect a signal when I have it at that resolution. The monitor is detected on the laptop. When I set the resolution down to 1920x1080 then the monitor does work.

The monitor also worked with my old thinkpad running Ubuntu 20.04.

The xps has an Intel UHD Graphics 630 and Nvidia GTX 1650, and is using nvidia-driver-470

xrandr output while monitor shows "No signal detected"

Screen 0: minimum 8 x 8, current 4480 x 1440, maximum 32767 x 32767
eDP-1-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 346mm x 194mm
   1920x1080     59.93*+
   1680x1050     59.95    59.88  
   1600x1024     60.17  
   1400x1050     59.98  
   1600x900      59.99    59.94    59.95    59.82  
   1280x1024     60.02  
   1440x900      59.89  
   1400x900      59.96    59.88  
   1280x960      60.00  
   1440x810      60.00    59.97  
   1368x768      59.88    59.85  
   1360x768      59.80    59.96  
   1280x800      59.99    59.97    59.81    59.91  
   1152x864      60.00  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   800x512       60.17  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   720x450       59.89  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   680x384       59.80    59.96  
   640x400       59.88    59.98  
   576x432       60.06  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
DP-1-1 disconnected (normal left inverted right x axis y axis)
DP-1-2 disconnected (normal left inverted right x axis y axis)
DP-1-3 connected 2560x1440+1920+0 (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440     59.95*+
   1920x1080     60.00    50.00    59.94  
   1920x1080i    60.00    50.00    59.94  
   1680x1050     59.88  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    60.00  
   832x624       74.55  
   800x600       75.00    60.32  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08 

This looks like your Dell Laptop's screen does not support this high resolution, but your external monitor does.

For example, if your laptop has a Full-HD 1920x1080 screen, it cannot display a 2560x1440 resolution. This happens despite the capabilities of your Laptop's graphics card - which can do this - proven by being able to use this resolution on your external monitor.

Often, a screen with a higher solution can display an input signal with a lower solution, i.e. you can display a VGA signal (640x480) on a Full-HD display (1920x1080). But not the other way round, i.e. displaying a Full-HD signal on a VGA screen.