Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Make sure your settings have not changed to print a booklet instead of single pages.
If your settings are correct and no joy, then I would try repairing Publisher/Office.
Reference: Repair Office: https://support.office.com/en-us/article/Repair-an-Office-application-7821d4b6-7c1d-4205-aa0e-a6b40c5bb88b
Here are the steps on how to repair Microsoft Publisher:
- Open the Control Panel.
- Click on Programs.
- Click on Programs and Features.
- Find the Microsoft Office application you want to repair, right-click it, and select Change.
- In the Microsoft Office Product Activation dialog box, select Quick Repair or Online Repair.
- Click Continue.
Quick Repair will fix any minor problems with the Office installation. Online Repair will download and install the latest version of the Office installation files.
Still no joy...check printer manufacturer for updated printer driver. Yes, it could be your printer even if the printer works ok with Word.
DavidF