Problem with downloading attach files.

Problem with downloading attach files.

Hello,
I am having problems with attachment on mails of zoho. If i attach a file for example an excel file .XLSX if i try to download the same file, the download box gave me a "FileDownload" with extension DOCX, as shown at the screenshot
 

This is happening to every mail that i have, in every pc.
Does anyone know how to fix it?
Thanks