Never mind, I have found the answer that was posted under the same question over 4 years ago.
Version: 11.8
A user has scheduled a report that generates around 5,500 records. However, when he receives the emailed .xlsx spreadsheet, the header displays "1 - 2000 of 5500," and only the first 2,000 records are included.
Is there a setting that limits this?
How can I remove this limit so she receives all the records?