Ubuntu – Black screen after installing NVIDIA drivers 390, 410, 415 for GeForce 1050 TI

Problem

I cannot get my NVIDIA 1050 TI to work with Ubuntu 18.04 and 18.10 (I updated, same issues). Every time I switch from the built-in drivers to the ones from ppa:graphics-drivers, a reboot will lead to a black screen, from which I can't get anywhere.

I always have to boot into recovery mode, purge the nvidia packages, and try again. My monitor is connected to the DP port on the NVIDIA card; it's an AOC 4K 60Hz display.

I have tried the following versions of the NVIDIA drivers via apt:

• 396
• 410
• 415

Update: The problem is not GDM3 or lightdm (I've tried both), it's actually that the screen where I get asked the LUKS password is not shown. When I type my password blindly, I can continue to the login screen!

Related questions / discussions

I have seen the following posts:

• Installing NVIDIA GEFORCE 1050 TI – Cannot Get To GUI — but with the built-in driver, the graphics card works. It's only when switching to the third-party drivers that the issue occurs.
• NVIDIA drivers 410 break Ubuntu 18.04 with GTX 1050 — doing this at least gets me to the screen where I can enter my LUKS password (albeit with the wrong display resolution), and it then proceeds to the Ubuntu logo, but the progress stops at three of five dots. Just uncommenting WaylandEnable gets me a black screen only, so it's probably the nvidia-drm.modeset=1 that changes… something.
• Black screen after install Nvidia Driver
• Black screen after reinstall/install nvidia driver
• Installing newest PPA driver for Nvidia (410) leads to black screen — I cannot even get to the login window

Some bug reports:

• A bug report here about the 410 drivers just leading to a black screen, without resolution
• Another one which was closed without resolution
• This one seems to be relevant,

Any idea what I could look for? Where would I find logs that give me an indication of the error?

More info

Detailed info about the device:

➜ lspci | grep -i vga
01:00.0 VGA compatible controller: NVIDIA Corporation GP107 [GeForce GTX 1050 Ti] (rev a1)

The problem is the same on both 4.15 and 4.18 kernels (18.04, 18.10). My current kernel:

Linux voltaire 4.18.0-13-generic #14-Ubuntu SMP Wed Dec 5 09:04:24 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

My apt-cache policy:

linux-headers-generic:
  Installed: 4.18.0.13.14
  Candidate: 4.18.0.13.14
  Version table:
 *** 4.18.0.13.14 500
        500 http://ubuntu.inode.at/ubuntu cosmic-updates/main amd64 Packages
        500 http://ubuntu.inode.at/ubuntu cosmic-security/main amd64 Packages
        100 /var/lib/dpkg/status
     4.18.0.10.11 500
        500 http://ubuntu.inode.at/ubuntu cosmic/main amd64 Packages

Output I get when installing the latest nvidia-driver-415 package:

Loading new nvidia-415.25 DKMS files...
Building for 4.18.0-13-generic
Building for architecture x86_64
Building initial module for 4.18.0-13-generic
Secure Boot not enabled on this system.
Done.

nvidia:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/4.18.0-13-generic/updates/dkms/

nvidia-modeset.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/4.18.0-13-generic/updates/dkms/

nvidia-drm.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/4.18.0-13-generic/updates/dkms/

nvidia-uvm.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/4.18.0-13-generic/updates/dkms/

depmod...

DKMS: install completed.
Setting up nvidia-driver-415 (415.25-0ubuntu0~gpu18.10.1) ...
Processing triggers for libc-bin (2.28-0ubuntu1) ...
Processing triggers for initramfs-tools (0.131ubuntu15) ...
update-initramfs: Generating /boot/initrd.img-4.18.0-13-generic