It appears that your file is still encrypted and protected. Currently, ADF does not support encrypted or protected Excel files out of the box. To handle such files, you may need to rely on additional functionalities, such as using Azure Function Apps to extract data or custom code to convert the encrypted Excel file to a normal one before copying.
To verify if your Excel file is encrypted, could you please try opening it both in ADLS and locally?
Links to help you :
https://learn.microsoft.com/en-us/azure/data-factory/format-excel