I installed 19.10 on a new Lenovo x1 Extreme.
I am unable to use an external display with either usb-c or hdmi. Only one display shows up in Display Settings. There is no movement in dmesg when connecting second display.
Proprietary drivers are installed (nvidia-driver-435).
My problem is that I cannot switch between NVIDIA gpu and Intel gpu. I am able to make different choices in the "NVIDIA X Server Settings" app. But, even after reboot these changes are not reflected in Settings -> Details which always says "Intel® UHD Graphics 630 (Coffeelake 3x8 GT2)".
$ sudo lshw -c display
*-display UNCLAIMED
description: VGA compatible controller
product: NVIDIA Corporation
vendor: NVIDIA Corporation
physical id: 0
bus info: pci@0000:01:00.0
version: a1
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress vga_controller cap_list
configuration: latency=0
resources: memory:cd000000-cdffffff memory:a0000000-afffffff memory:b0000000-b1ffffff ioport:3000(size=128) memory:ce080000-ce0fffff
*-display
description: VGA compatible controller
product: UHD Graphics 630 (Mobile)
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
logical name: /dev/fb0
version: 02
width: 64 bits
clock: 33MHz
capabilities: pciexpress msi pm vga_controller bus_master cap_list rom fb
configuration: depth=32 driver=i915 latency=0 mode=1920x1080 visual=truecolor xres=1920 yres=1080
resources: iomemory:600-5ff iomemory:400-3ff irq:153 memory:6040000000-6040ffffff memory:4000000000-400fffffff ioport:4000(size=64) memory:c0000-dffff