Currently in the standard some downloads are the result of navigation and others are the result of the download attribute, which ostensibly fetches directly, but can also navigate, e.g., if you use <a download=x href=https://www.example.com/>test</a> outside of example.com.

I suspect that due to redirects and such it really should just be an input to the navigate algorithm and therefore the mode ought to be "navigate".

This disconnect has a broader impact now due to the existence of the Sec-Fetch-Mode header, see https://bugzilla.mozilla.org/show_bug.cgi?id=1637747.

(I'm pretty sure this was discussed before, but I cannot find the issue.)

cc @mikewest @ckerschb