Unable to install Nvidia drivers on Kubuntu (KDE Neon 5.19)

I have some problems installing Nvidia drivers on my Kubuntu system and to get them working (GPU-Model: GeForce GTX 980 Ti). I tried it first in the standard way: $ sudo add-apt-repository ppa:graphics-drivers/ppa $ sudo apt-get update $ sudo apt-get install nvidia-driver-450 The installation finished, but after restarting, the new drivers don't work very well. I'm using a 4K monitor with 3840x2160 (16:9) resolution, but with the driver in use, it only allows for a resolution of 1024x768 (4:3), so my whole screen gets distorted. Also, the command nvidia-smi fails: NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running. Furthermore, after removing the drivers manually and restart, everything is back to normal. I tried with this method instead: $ sudo ubuntu-drivers autoinstall, but I get the same results. Then, I tried to execute the runfile provided by NVIDIA on their download site, but it fails because it is unable to disable Nouveau (the current Kernel driver in use). I also executed this command: lspci -vnn | grep VGA -A 12 to check. This is what I get when running normal: And here the same output with NVIDIA drivers enabled: 01:00.0 VGA compatible controller : NVIDIA Corporation GM200 [GeForce GTX 980 Ti] [10de:17c8] (rev a1) (prog-if 00 [VGA controller]) Subsystem: NVIDIA Corporation GM200 [GeForce GTX 980 Ti] [10de:17c8] Flags: bus master, fast devsel, latency 0, IRQ 11 Memory at f6000000 (32-bit, non-prefetchable) [size=16M] Memory at e0000000 (64-bit, prefetchable) [size=256M] Memory at f0000000 (64-bit, prefetchable) [size=32M] I/O ports at e000 [size=128] Expansion ROM at 000c0000 [disabled] [size=128K] Capabilities: Kernel modules: nvidiafb, nouveau 01:00.1 Audio device : NVIDIA Corporation GM200 High Definition Audio [10de:0fb0] (rev a1) Subsystem: NVIDIA Corporation GM200 High Definition Audio [10de:17c8] Any advice how to get the NVIDIA drivers installed and working on Kubuntu? I tried pretty much every installation guide, but none of them really worked.