Xubuntu - Second monitor not recognised by OS - xrandr addmode kinda works

Igel H830C have one display port and one DVI-I port. I have connected two monitors via adapters (HDMI to DVI-I and HDMI to display port). Monitor (DELL U2520D) is working without any problems. However when I'm connecting 6.5" LCD (board pcb800099) its not recognized by OS (Xubbuntu - Ubuntu 22.04.2 LTS) at all. I have checked both adapters and 6.5 LCD on PC/laptop with windows and they are working correctly.

sudo xrandr

returns:

VGA-1 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
HDMI-2 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 553mm x 311mm
   2048x1080     60.00    24.00  
   1920x1080     60.00*   60.00    50.00    59.94    25.00    24.00    23.98  
   1920x1080i    60.00    50.00    59.94    50.00  
   1600x1200     60.00  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x576i      50.00  
   720x480       60.00    59.94  
   720x480i      60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08 

sudo xrandr --listmonitors

returns:

Monitors: 1
 0: +HDMI-2 2048/553x1080/311+0+0  HDMI-2

sudo lshw -C video

returns:

*-display                 
       description: VGA compatible controller
       product: Atom Processor Z36xxx/Z37xxx Series Graphics & Display
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       logical name: /dev/fb0
       version: 0e
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi vga_controller bus_master cap_list rom fb
       configuration: depth=32 driver=i915 latency=0 resolution=2048,1080
       resources: irq:100 memory:d0000000-d03fffff memory:c0000000-cfffffff ioport:2050(size=8) memory:c0000-dffff

I was trying something like that: xrandr --output HDMI-1 --mode 800x600 but got: xrandr: cannot find mode "800x600"

then I tryed:

xrandr --addmode HDMI-1 800x600

and suprise suprise it have worked! Kinda, Screen is displaying, but resolution is off, and "Display" app still do not recognize this screen.

Additional info:

Linux pc-H830C 5.19.0-38-generic #39~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Fri Mar 17 21:16:15 UTC 2 x86_64 x86_64 x86_64 GNU/Linux