Dual screen issue after installing driver.

[mgjadoul]

I have a Zbook 17 G4 with a Nvidia Quadro M1200 Mobile and a Intel HD 630 card.
I use a Thunderbolt 3 docking station and an external display is connected on it.
I use fedora 30 with Wayland and can display using Intel display driver. Both screens, internal and extenal work in this setup. I have some time issue on the external screen not detected after suspending the laptop. But it is mostly usable as a reboot allows me to be in dualscreen again.
So this first setup is not using Nvidia driver which is not installed at all.

I want to use my Nvidia card to test some cuda developement, but I do not need the nvidia driver for displaying...
As soon as I install the nvidia-driver, I loose my external screen and rebooting does not return it back. I tried blacklisting nvidia-drm + nvidia-modset module (which I do not need....?) but it does not solve the issue and my external screen is still black.

I use my external screen of course only If I am connected to powersupply..... but I suspect there is something related to powersaving and cutting power on the nvidia card when nothing run on it..... May be disabling the powersaving on the nvidia card when the system is connected to the powersupply would work.... But I do not know how to do....

Or may be there is some other issue / parameters involved. Any idea?