My guess is how gedit uses printer versus how other applications use printer.
When you go to print preview do you see your source?
Nothing to do with brand of printer, system or OS since it does work correctly for every other application.
One old bug has this maybe for clues.
https://bugs.launchpad.net/ubuntu/+s...ps/+bug/570522
Normal instruction here.
"Printing To Paper
You can print your documents to paper using a local or remote printer. To print a file:
Select File ▸ Print ▸ General.
Select the desired printer from the list of printers available.
You can preview the file using Print Preview and once you are satisfied with the settings, click Print to send the file to printer.
"
https://help.gnome.org/users/gedit/s...inting.html.en