The Nvidia Driver Assistant does not support Manjaro or Arch.
We are aware that upstream is using 580xx as the next legacybranch, but Manjaro Team has chosen to change that recommendation to 575xx.
The choice is likely to become a target of debate at various fora, but it is a deliberate choice made to ensure a reasonable stable experience for Nvidia users. The phrase ‘reasonable’ should be seen in the context of Nvidia drivers.
Manjaro Team is using a slightly modified version of the script, the source is available on Gitlab.
Due to the amount of issues with the 580-series, especially the issues with the Xfce desktop Manjaro Team has also implemented a modified Manjaro specific database; where the Nvidia recommendation for 580.xx has been changed to Manjaro recommendation of 575.xx.
Manjaro provides the rolling open driver - known as ´linux-nvidia` which is now at 590.
If your Maxwell, Pascal or Volta card was working as expected with 580.xx driver you will still be able to use that driver, by grabbing the nvidia-580xx-dkms buildscript from AUR.