how to download files in native format, Safari downloads everything as html (txt, py, doc, etc.)

I'm new to the Mac world. I've been using Safari for everything (school and work). The problem I'm having is that every file that I download from Safari is automatically downloaded with a different name and file extension. For example, if the file to download is named "project6.txt" it downloads it as "true.html". The same thing happens with all other file extensions I've been working on.

I've tried to just manually change the file name and extension to match the file I'm downloading but that doesn't work either.

The only workarounds I've found that work but are not practical a) download the file using my old Windows laptop and sending it to my email, downloading it from my Mac and them work on the files or b) download the file using another browser (which I don't want to do).

I'm sure there's a solution but I can't find one.

Any help will be much appreciated.

Thanks!