If your already installed printer that has worked before, when you re-connect it to USB, it will not print - then try these steps:
1. Open Preferences and then Printers
2. Chose your printer and rightclick on it and chose Properties
3. Click on Policies and make sure that Enabled has a checkmark
4. Click Apply and go back to Settings and Print a testpage
Now it should work.
This might happen if you connected the printer to other USB port than the one you installed it to. Can also happen when you get updates to CUPS.