When using the feature "Export to Excel" (E2E), only the first 300 rows are returned. If you export a list of projects, for example, only the first 299 projects are exported (plus the header row).
This limit cannot be changed or disabled. The intention of the option for 'Export to Excel' or 'Export to PowerPoint' is to provide a nicely formatted output. Therefore, a restriction on the number of rows to be exported into this format is implemented.
Use "Export to Excel (Data Only)" instead, as it does not have a 300 row limit. This option allows the user to export the numerical data into a spreadsheet and then it can be formatted as desired.