Driver current? https://support.brother.com/g/b/downloadtop.aspx?c=us&lang=en&prod=mfcj470dw_us_eu_as Windows home or pro? If windows, what security software besides MS Defender are you running? What version of Firefox? What does not working in Firefox mean? Can you show us the issue?

Printer works in chrome, test page etc but not in FIREFOX......Windows 11 version 24HR, Printer BROTHER MFC-J470DW. Will print test page OK.

Hey, had the same issue – turns out Firefox was set to "Save to PDF" by default. Just go to File > Print, then click on "Printer" and make sure your Brother printer is selected instead of "Microsoft Print to PDF" or anything else. After that, it worked fine for me. Hope that helps!