Picture didn't attach

see this page:

• https://support.mozilla.org/en-US/kb/fix-printing-problems-firefox

OR

• https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save

I've been through those pages and prompts already. None of that helps at all.

Someone out there has to have a fix. These receipt printers are widely in use, and I've been reading of FF's ongoing problems with specifically this brand. Maybe we just need to switch browsers?

try to Reset Firefox it can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

• Go to Help > Troubleshooting Information.
• Click the "Reset Firefox" button.

Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.

Firefox will open with all factory defaults applied, and try change printer setting.

Further information can be found in this page:

• https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings

I’ve been through that as well. Still not working like it used to.

Rusty Shackleford said

I change settings to 72mmxReceipt and it holds for that print job only, but will not save. I never had to do this before. Issue is only in FF, other browsers and desktop printing is unaffected. Problem started after recent update.

I doubt that is a FF problem here. I had my two network printers attached by my router and have no loss in print settings. Those settings come from the printer software not from FF.

What you should do is uninstall FF completely and delete the Mozilla folder and reinstall FF to see if it is really a FF problem or Printer software problem.