Why did my Brother MFC-J460DW stop working?

Hi,

The Brother MFC-J460DW is mentioned in About AirPrint - Apple Support as a model supporting the driverless AirPrint technology, so it should work without additional drivers if the printer and the computer are connected to the same network (Wi-Fi router).

Has anything been changed regarding router, settings, et cetera?

To begin with, you may want to try the following power-cycling sequence: Power off the router, the printer, the computer, and all other devices/computers. Wait two to three minutes. Power on the router. Wait two to three minutes. Power on the printer. Wait a minute or two. Power on the computer. Finally, power on all other devices/computers.

If necessary, reset the printing system and re-add the MFC-J460DW as an AirPrint printer.

Reset the Mac printing system to solve a problem - Apple Support

Add a printer on Mac - Apple Support

have you tried to get brothers latest driver for your operating system

Downloads | MFC-J460DW | United States | Brother

my old Samsung wifi printer had to be assigned a static ip address to work

they had some tool that would sweep the network looking for MAC addresses and find the printer

and one could assign it an ip address which was required in order to install the printer driver, maybe it's something simular