Teaching with Moodle

This was exceptionally hard to find and admittedly its made me think of a few other things to search the code for...

When we export data from a table we can pick the file format and the download is indeed in that format, however its saved as "Hamp" with no extension. Giving it the correct extension, .xlsx, .ods, .csv etc seems to then open fine, but surely there is a setting somewhere I'm missing.... And no, the github repo doesnt appear to have the word "Hamp" in it either. 

Please advise, I'm running 4.0.2 ( I believe )