something has stopped AirPrint capability on both my Brother and Epson printers from my iPhone. it has been working for the past 2 years. but now not. both printers are AirPrint capable and WiFi network has remained the same. firmware for both printers is "up to date" which only means that the printers' firmware might need to be updated by the manufacturers to adjust for something that was done in iOS 11.4.1 any suggestions?