Xbox One on 1440x900 monitor

I am running my xbone on a 1440×900 monitor with an HDMI to DVI cable (monitor link: http://static.highspeedbackbone.net/pdf/Gateway_FPD1975W_Manual.pdf).

My Playstation 3 is able to output 1080p to this monitor (with the same cable, if that matters). I think the monitor downscales the PS3 output automatically. However, the xbone will only output 480p when connected to this monitor. I don’t understand why the PS3 will output 1080p to this monitor, but the xbone will not. I’ve tried resetting the xbone display output, but it still outputs at 480p. Does anybody know of a way to force the xbone to output 1080p or something? I can’t think that it’s a problem with the monitor considering it will automatically downscale the PS3 output properly.