mail merge exclude recipient grayed out

I’m doing a mail merge using a Libreoffice template I created for envelopes. For the database I created a Libreoffice database from a Libreoffice spreadsheet. I opened the template, clicked the Data Sources icon found the correct database, and all the correct records are showing.

I have done this procedure many times successfully, but now the Exclude Recipient option is grayed out. I am using version

Any help would be greatly appreciated.