Cannot print to 3x5 index card

[SkippyT.Wonderlizard]

I created a custom page format, with 3x5 landscape paper. When I click “print,” in the print dialog, the paper is US Letter.

The default paper for the printer has been changed to a custom paper size, 3x5.
[I wanted to show a screenshot; but as a “new user,” I can include only one image.]
Exporting to PDF still results in US Letter sized product.
Is there any way to fix this?

Running mac os 14.6
Brother 3390DW printer
Version: 24.2.3.2 (X86_64) / LibreOffice Community
Build ID: 433d9c2ded56988e8a90e6b2e771ee4e6a5ab2ba
CPU threads: 16; OS: macOS 14.6; UI render: Skia/Raster; VCL: osx
Locale: en-US (en_US.UTF-8); UI: en-US
Calc: threaded

[EarnestAl]

Have you set the paper size in the printer itself when you loaded the index cards?

You have the box Use only printer tray from printer preferences ticked

What is the smallest size stock that your printer will take?