Table Objects in Co-Authored Excel Spreadsheet

I have an Excel worksheet used to track specific events with multiple users providing updates. 'Tracker' is implemented as an Excel table with Data Validation and Conditional Formatting features.  The worksheet has been shared as a Co-Authored file on our Organization's OneDrive.  The Users to which I have enabled access, have edit rights to the file.

Problem is that these authorized Users cannot extend the table by tabbing beyond the current last row and if they manually add entries in the row below the current last row, this information is not incorporated into the table.  I, as the original author / owner of the file, can perform these operations without issue.

Why can't other Users extend the table?