who is Jonathan King?

I’ve been asked to help with an issue using calc. The person concerned has been using open office and libre office for some years during which time they have used a template for invoices in calc that they have copied and reused keeping a copy of each yearly invoice but in the last few days additional information is showing up in the documents. It appears in all the documents they open.
Name: Jonathan King
Address 722 Moss Bay Blvd WA 98033
Other details such as New York are also showing up along with invoice items of "copies of Resume , and “bound copies of report”

This information is showing in place of the real name and address of the person in the invoice.

The spreadsheets are saved with an xlsx extension which may have been set as the default the last time Libre office was upgraded. Its currently version 5.1.0.3

I’ve searched the internet but can only find this one reference

https://listarchives.libreoffice.org/global/users/msg34585.html

ANy help appreciated

Have you examined the invoice Template to see what’s typed there?