Maybe this is an Xorg issue ? I've tryed creating the Xorg cofig file for the second monitor as people on forums pointed that sometimes xorg point torward the wrong nvidia stuff and it outputs this :
X.Org X Server 1.21.1.15 > X Protocol Version 11, Revision 0 > Current Operating System: Linux debian 6.12.10-amd64 #1 SMP > PREEMPT_DYNAMIC Debian 6.12.10-1 (2025-01-18) x86_64 > Kernel command line: BOOT_IMAGE=/boot/vmlinuz-6.12.10-amd64 > root=UUID=2a5eb3de-eb53-44bd-936f-dc7aaef7701f ro quiet > xorg-server 2:21.1.15-2 (https://www.debian.org/support) > Current version of pixman: 0.44.0 > Before reporting problems, check http://wiki.x.org > to make sure that you have the latest version. > Markers: (--) probed, (**) from config file, (==) default setting, > (++) from command line, (!!) notice, (II) informational, > (WW) warning, (EE) error, (NI) not implemented, (??) unknown. > (==) Log file: "/var/log/Xorg.2.log", Time: Thu Jan 30 17:51:37 2025 > List of video drivers: > amdgpu > ati > intel > nouveau > nvidia > radeon > vmware > modesetting > fbdev > vesa > (++) Using config file: "/root/xorg.conf.new" > (==) Using system config directory "/usr/share/X11/xorg.conf.d" > Number of created screens does not match number of detected devices. > Configuration failed. > (EE) Server terminated with error (2). Closing log file.