My problem is multiple displays are not detected since i reinstalled.
OS: Ubuntu 24.04.1 LTS
WS: Wayland
Machine: ASUS Zenbook 16
Secondary screen ASUS Zenscreen MB16AV
In Settings/displays is “Join” or “Mirror” selected? “Mirror” will remove the picture of the second display (since both displays show the same thing). Also, under Wayland with Nvidia video, you’d need the 565 Nvidia driver from the graphics-drivers PPA to get “Join” to work right.
I do not see any option in settings.
Plus, I ran
supercomputer@Zenbook-S-16-UM5606WA:~$ xrandr
Screen 0: minimum 16 x 16, current 2880 x 1800, maximum 32767 x 32767
None-1 connected 2880x1800+0+0 (normal left inverted right x axis y axis) 762mm x 476mm
2880x1800 59.97*+
2048x1536 59.95
1920x1440 59.97
1600x1200 59.87
1440x1080 59.99
1400x1050 59.98
1280x1024 59.89
1280x960 59.94
1152x864 59.96
1024x768 59.92
800x600 59.86
640x480 59.38
320x240 59.52
2560x1600 59.99
1920x1200 59.88
1680x1050 59.95
1440x900 59.89
1280x800 59.81
1152x720 59.97
960x600 59.63
928x580 59.88
800x500 59.50
768x480 59.90
720x480 59.71
640x400 59.95
320x200 58.96
2880x1620 59.96
2560x1440 59.96
2048x1152 59.90
1920x1080 59.96
1600x900 59.95
1368x768 59.88
1280x720 59.86
1024x576 59.90
864x486 59.92
720x400 59.55
640x350 59.77
Screenshot of display setting
Hello @bashn,
Question for you that I’m curious. 
Where you using HDMI, DisplayPort, or Type-C and did you re-plug it to see it fixes an issues, if that fails, try relaunch that settings to see problem solved.
For Type-C display, my Acer Nitro 5 used to support Type-C as a display and back in last year’s December (December 2024), it’s no longer capable of being used as a display for certain monitors with Type-C display. If it has HDMI or DisplayPort, try one of them to see that solve issues for you.
I hope this solve issues for you, plus, ZenBook shouldn’t have Type-C slot available but it should have HDMI. I’m not making you have to do it, if you want to test that, that’s your choice (Especially for my curiosity). 
So that way I’m not wasting your time, stay tuned.
Your device is probably called ASUS Zenbook S 16 OLED UM5606WA which it has a maximum resolution around 3K resolution (2880x1800) at 120Hz of Framerate, and I can see yours is only at 60Hz rather than 120Hz maximum which I’m not sure why.
I have both cables USB to c-type or c-type to c-type given while getting the screen. It worked for previous installation, works perfectly for windows with same port.
The error message in the screen is :
Your device does not support DP Alt mode. Please install the latest driver and try again.
Well, that’s a shame. 
Did you update an AMD Graphics driver?
If so, then reboot Ubuntu to see if that solved issues.
If that fails, try this command on a terminal.
sudo ubuntu-drivers autoinstall