Steps to reproduce the issue

Install Joomla 4.1-dev
Install sample data
Create EDITOR level user
Login to FRONTEND
Click Single Article in the right menu
Click EDIT
Go to publishing tab - NOTE category is "Park Site (en-GB)"
Click Save As Copy button

Expected result

Article saves as a copy

Actual result

"Save failed with the following error: Category is required."

Category is now "Uncategorised"

System information (as much as possible)

Additional comments