Problem with xorg tryng to dual head setup with two graphics cards (intel and nvidia)

Hello to everyone.

What I'm trying to do is to correctly configure the file xorg.conf because
I want to use two gpus at the same time connected to two different monitors
while using FreeBSD 13.1. It could be useful when I want to make some 3d
modelling using Blender on the first monitor / gpu [nvidia 1060 or Intel
UHD graphics 630] and using the second one (nvidia 1060 or Intel UHD
graphics 630) to watch some tutorials. I've also got a third gpu (geforce
RTX 2080 ti) ,but I want to keep it free to be passed through on a bhyve
virtual machine. On the BIOS I've configured the Nvidia Geforce 1060 as the
GPU with which the PC boots. So,this is the scheme that I want to follow :


1) monitor AOC -> hdmi cable ---> gpu nvidia geforce 1060

2) monitor Samsung SynchMaster ---> hdmi cable ---> gpu intel 'CoffeeLake-S
GT2 [UHD Graphics 630]'

3) gpu geforce RTX 2080 ti without monitor,used only to be passed thru with
bhyve


Actually I'm using this xorg.conf :
https://pastebin.ubuntu.com/p/DhW6RHS3zb/

instead this is the Xorg.0.log file :
https://pastebin.ubuntu.com/p/YtdPq9fngQ/


In front of me I have the AOC monitor connected to the HDMI port of the
Geforce 1060. On my right I have the monitor samsung syncmaster,that's
connected to the HDMI port of the intel GPU. The 3 gpu (Geforce RTX 2080
ti) is non connected to any monitor because I want to use it to be passed
thru on a bhyve vm. What happens is that the samsung monitor works
partially. The only 2 apps which can be directed to it (it is attached to
the Intel GPU with the HDMI cable) are :


[marietto@marietto ~]$ export DISPLAY=:0.1 ; konsole

and :

[marietto@marietto ~]$ export DISPLAY=:0.1 ; chrome

(firefox can be displayed only on the screen 0 : don't know why)


Here you can find the list of every PCI device attached to my PC :

https://pastebin.ubuntu.com/p/Gx5DqckFQP/


I can export some applications to the DISPLAY=:0.1 (monitor Samsung
SynchMaster ---> hdmi cable ---> gpu intel 'CoffeeLake-S GT2 [UHD Graphics
630]). But this kind of usage is not comfortable at all. Infact I can't run
another session of xorg because it says that one session is already
running. Only some applications are displayed over it and If I invert the
cable and the drivers on the xorg.conf file,placing as primary GPU the
intel gpu attached to the AOC monitor and as secondary GPU the nvidia 1060
attached to the samsung syncmaster,the behavior is the same,with the
difference that I've inverted the monitors. I've tried to enable
xinerama,but it does not work well. It freezes the mouse and
anyway,attaching virtually two screens into only one is ridiculous,because
they aren't attached physically. What I want to do is to be able to do some
tasks on monitor 1 and some different tasks on monitor 2.


# xrandr -q

Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767
DVI-D-0 disconnected (normal left inverted right x axis y axis)
DP-0 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected 1920x1080+0+0 (normal left inverted right x axis y
axis) 598mm x 336mm
   1920x1080     60.00*+  59.94    50.00    60.00    50.04
   1680x1050     59.95
   1440x900      59.89
   1280x1024     75.02    60.02
   1280x960      60.00
   1280x720      60.00    59.94    50.00
   1024x768      75.03    70.07    60.00
   800x600       75.00    72.19    60.32    56.25
   720x576       50.00
   720x480       59.94
   640x480       75.00    72.81    59.94    59.93
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 disconnected (normal left inverted right x axis y axis)
DP-4 disconnected (normal left inverted right x axis y axis)
DP-5 disconnected (normal left inverted right x axis y axis)

arandr says that the only monitor connected is the HDMI-0,the monitor AOC
connected to the nVidia 1060 gpu. But if I invert the drivers on xorg.conf
and the cables,the only monitor connected will again be the HDMI-0,but this
time it will be the Samsung Synchmaster.

The reason for this behavior could have been explained here :

https://forums.freebsd.org/threads/dual-head-setup-with-two-graphics-cards.62886/post-363187

Anyway,I don't have a solution. Do you ?
-- 
Mario.