I installed a more recent version of hplip than the one distributed with 18.04, which made it impossible to install hp-plugin properly. So I want to get rid of the updated version and reinstall the version that came with 18.04.
I tried both sudo apt remove hplip and sudo apt purge hplip, then in both cases reinstalled with sudo apt install hplip.
But when I run hp-plugin after reinstall, the framework listed is still the updated version instead of the version from the Ubuntu repositories. Besides, the hp icon in the notification area is still there as well, so clearly not everything has been removed.
What can I do to either 1) completely remove all the components from the updated version or 2) install the version from the repositories in a way that will overwrite all the updated components?
In other words, how can I effectively completely replace the updated hp drivers and software with the ones from the repo? I'm getting so fed-up that I am considering reinstalling Ubuntu from scratch, which would be an humiliating defeat...
EDIT: I found a convoluted way to fix it (see in the comments below), but a shorter fix would have quite possibly been to simply add sudo apt install --reinstall hplip-gui in my reinstallation process. While the developer portal has a single package, ubuntu separates hplip and hplip-gui!