It appears that it is possible to stop the flickering by forcing the restart of X with Crtl+Alt+Bksp, this is by no way a decent workaround but eventually it stabilizes and I get three independent screens working properly.
My hardware is a Lenovo Thinkpad P50 with nvidia Quadro M1000M connected to a Lenovo Thinkpad Dock, which in turn connects to two Lenovo ThinkVision via display port to DVI-D connecters.
I am running Ubuntu Gnome 17.04 with nvidia driver 375.39-0ubuntu5.
It appears that it is possible to stop the flickering by forcing the restart of X with Crtl+Alt+Bksp, this is by no way a decent workaround but eventually it stabilizes and I get three independent screens working properly.
My hardware is a Lenovo Thinkpad P50 with nvidia Quadro M1000M connected to a Lenovo Thinkpad Dock, which in turn connects to two Lenovo ThinkVision via display port to DVI-D connecters.
I am running Ubuntu Gnome 17.04 with nvidia driver 375.39-0ubuntu5.