18.04 - After installing ppa nvidia-390 graphics drivers, switching to intel graphics card results in nvidia drivers not being loaded at all. kubuntu 18.04LTS

When switching prime profiles with the Nvidia x-server settings to internal intel graphics card, I am unable to switch back to the dedicated graphics card.
This is in part because the Nvidia driver does not load at all. The only error I get is the following while trying to start the nvidia x-settings;

~$ nvidia-settings
ERROR: NVIDIA driver is not loaded
ERROR: Unable to load info from any available system

specs;
(NEOFETCH)

ccpeters@ccpeters-Lenovo-ideapad-510-15ISK
OS: Ubuntu 18.04 LTS x86_64
Host: 80SR Lenovo ideapad 510-15ISK
Kernel: 4.15.0-20-generic
Uptime: 17 mins
Packages: 2465
Shell: bash 4.4.19
Resolution: 1920x1080
DE: KDE
WM: KWin
Theme: Breeze [KDE], Breeze [GTK3]
Icons: Breeze [KDE], Breeze [GTK3]
Terminal: konsole
CPU: Intel i7-6500U (4) @ 3.100GHz
GPU: NVIDIA GeForce 940MX
GPU: Intel Integrated Graphics
Memory: 857MiB / 7882MiB

I'm using kde plasma 5.12 on kubuntu 18.04 LTS, with the nvidia-390 drivers.
I have overall noticed a lot of bugginess with nvidia under the new ubuntu 18.04 and have seen many bug reports of other people having problems as well.
This is probably completely nvidia's drivers fault.