13x19 paper in Epson XP 15000 only printing 8.27" wide

I’m using Libreoffice Version: (x64)
Build ID: efb621ed25068d70781dc026f7e9c5187a4decd1
Running on Windows 10 Pro V1803.

I just bought an Epson XP 15000 printer. Other printing jobs work fine, but when I print a 12"x12" image on 13x19 paper, it instead prints an 8+ inch section of the image, perfectly centered on the paper. All of the Epson settings seem correct - in the printer preferences, document size is set to 13x19. I can’t find any settings either in Epson’s properties or in Libreoffice that is causing this. Libre’s page format is set to 13x19, with .25" margins all around.

When I export the image as pdf, it prints perfectly. If I HAVE to, I can do that, but I’d prefer to print straight from libreoffice.

Any ideas on how to get this to work?