[jamies]

I found this on their FAQ: "There have been some problems with downloading .zip files from Safari. The download is tested to work in Chrome and FireFox."

[bongobingo1]

Truly the Internet Explorer of the modern age.

(Perhaps this is Safari passing the download through some more rigorous "malware checker" on macOS that Chrome/Firefox doesn't have access too?)

[bobbylarrybobby]

There is JS that combines the files into a zip before downloading. I'd imagine that it's that code whose behavior differs between browsers.