Hah, I can’t believe I just lost hours debugging the same issue. Tried ipp, socket, tcp…
Your post had the answer: one single line solved everything: pacman -S cups-pdf
My printer is a Brother 1622WE which is about the same as yours, it just has a scanner included. I just upgraded it from Brother 1210WE two months ago.
Very good printers IMO, once they are set up you can forget them, just print away.
I also have a Brother laser HL-L2320D and Cups installs with the online installation. I only have to install the driver from the AUR and everything is installed. I just checked and cups-pdf is there also.
Thank you for the link to your old post. Although it wasn’t related to my printer issue (in my case I had to install the 32 bit cups libs) it did solve a different network issue I was experiencing