This is a fresh Mageia 6 install with Plasma. My All-in-One HP OfficeJet 4500-G510g isn't working properly. I installed it through hp-setup (HP Device Manager) and it's connected through USB, but somehow when I call the Print dialog with Ctrl+P only Firefox detects it. On LibreOffice and all programs in the Plasma desktop (Okular, Gimp, KHelpCenter, Konsole...) it doesn't show up on the printer list. By the way, the Print dialog takes about five to six seconds to appear.
The printer appears on MCC and CUPS web interface, where it shows these features:
Description: Officejet_4500_G510g-m
Location: Fractal
Driver: HP Officejet 4500 g510g-m, hpcups 3.17.4 (color)
Connection: hp:/usb/Officejet_4500_G510g-m?serial=CN0A8F214T05CQ
Defaults: job-sheets=none, none media=iso_a4_210x297mm sides=one-sided
Does anybody know what's going on and how to troubleshoot this?