I've been trying to print on 4"x6" paper from the upper cassette of my iP7250. In the printer preferences I choose 4"x6" and a message tells me that the upper tray is selected. But if I close the preferences and reopen them, it tells me that it will print on A4 paper and that the lower tray is selected. If I do try to print after selecting the upper tray, it will still try to print from the lower tray.
The application I am trying to print from is Affinity Photo. I made sure to enable the fit-to-paper option in the application's print dialogue.
How can I get the printer to print from the upper tray?