Minor issues - attachments Firefox

I find it strange, HC support says its normal, browser issue, but Im sure there must be a way to fix, as other programs dont have this problem!

If you try to download some attachment in HC ticketing system via firefox, such as "file test.docx", this file is downloaded without the suffix...
 
HC, pls, there must be some easy way to fix this annoying issue..
 
Thanks.