Second screen goes white

I have a Dell G3 3590 and used to work with Windows and a second screen (Samsung Monitor via HDMI), which always worked great. But now, I switched to ZORIN 17.2, and when I turn it on, both screens work until the login screen. After that, both displays show the same image, but once I log in, the second monitor turns almost completely white (only a small portion at the top shows the image). Does anyone know what might be happening?

are you on wayland or Xorg ?

Welcome to the Forum!

Is it possible that You post a Picture of the Monitor and how the Display with this Issue looks?

Wayland

can you see if it works on xorg ?


I changed to xorg and the screen turned green, as you can see in the image

go to display settings and see if 2nd monitor's resolution and refresh rate is set to recommended
also is your system updated ?
run

sudo apt update
sudo apt upgrade
sudo apt dist-upgrade

reboot after that

Just did it, nothing changed

Did You tried it with another HDMI Cable and maybe on another HDMI Port?

I have only 1 port on my PC, but the monitor was working fine with windows. I changed to zorin this friday, but i've been using this monitor for a year and when i turn the PC on, before I log in, the monitor works perfectly

So that machine has Nvidia graphics, Yes?
Which driver are you using?

you can install the latest Nvidia driver with

sudo apt update
sudo apt install nvidia-driver-530

reboot