Many thanks CathyO
We have downloaded the drivers for both Windows and macOS from the Xerox website. On Windows we use the driver version 5.617.7.0N and on macOS 5.7.2.
On Windows, in the default driver settings, the type of material is set to "standard media" (don't know the exact translation, in German it's "Standardmaterial". Except for the page imprint, which we changed from 2-sided to 1-sided, all other settings are set to the default values.
It sounds like you may be using the driver that came with your OS. I would recommend to uninstall and reinstall the printer using the Xerox Print Driver.
Our printer has two paper trays. Tray 1 contains A4 paper 80g/m2, Tray 2 contains A3 paper 160g/m2. Since we encountered problems with fusing, we changed the paper type of tray 2 from plain paper to lightweight cardboard. Since then, however, the automatic paper tray selection no longer works because the driver wants to print on plain paper by default. Unfortunately, in the driver (on both Windows and Mac) I have not found a way to define that A3 paper should default to lightweight cardstock.
How do we have to proceed so that the automatic paper tray selection works with both A4 plain paper and A3 lightweight cardstock?