For what it's worth, this bug is still present in Kubuntu 20.04. Deleting Print-Manager and reinstalling after reboot (and deleting printers) ---as advised above--- seems to have solved the problem---for now.
For what it's worth, this bug is still present in Kubuntu 20.04. Deleting Print-Manager and reinstalling after reboot (and deleting printers) ---as advised above--- seems to have solved the problem---for now.