What you describe sounds like the printers installed options were not enabled properly by the operating system during the installation of the printer. Very often I install printers on macOS and the driver installation wizard will show that all of the options are enabled, but when I check in System Prefences they are not enabled. So I am in the habit of always checking what shows up in System Preferences after installing a printer. If I'm correct this should be easy to resolve by doing the following.
Open System Preferences
Select Printers & Scanners
Click on the printer in the left side of the window to select it
Click on Options & Supplies...
In the new window that opens click on Options
Change the Paper Trays: setting to show 4 Trays
After doing that your additonal trays should be available in the Paper Feed menu when printing. While you're in the options section also check the various other options like the finisher, if you have one, and hole punching. Enable anything that your printer has installed on it.
After a few coworkers upgraded or recieved new computers on Catalina the option under Paper Feed shows trays 3 & 4 grayed out. We have deleted the printers from the System Preferences, installed new Catalina drivers from Xerox and the trays remained grayed out.
Anyone else having this issue?
Any suggestions to resolve?
Thank you in advance.