When importing the Auth report csv file, you are unable to format 'username' and 'sim number' columns to display the correct format as per instruction in support article P8Auth Report - Formatting MSISDN and SIM Card Number Columns
By default, newer versions of Excel Office 365 do not support legacy import functions. These functions are required to format the Auth report correctly.
To resolve this issue, follow the below steps to ensure the legacy import function is enabled.
Step 1: Open Excel and from the top menu select 'File' -> then 'Options'
Step 2: Select 'Data' -> then tick the box 'From Text (legacy)' located under the section 'Show legacy data import wizards'. Once done click 'OK'
Step 3: Open a new file in Excel, Select 'Data' tab -> 'Get Data' button.
If you see the options 'Legacy Wizard ' and 'From Text (Legacy)' then you can continue with the import article P8Auth Report - Formatting MSISDN and SIM Card Number Columns
If not then please review steps above to ensure you have enabled the option correctly.