Saver timeout on some files, no intermediate progress

I just implemented dropbox Saver on our site, and I'm having some trouble.

I tested with two files:

The first file is about 12MB and downloads from the provided URL to the dropbox account successfully in about 5 seconds.

The second file is about 20MB and times out after 5 minutes.

I manually tested both URLs (in incognito mode on Chrome) and both resolve properly.  The bigger file takes about 30-40 seconds to download from the URL to my laptop.

Strangely, when downloading the file that successfully downloads, I get a progress indicator every few seconds from the progress event.  The progress starts at 0, every few seconds I get another progress of 0, and then at the end I get a progress of 1.  It's never anything in between 0 and 1.  Is there a way to get decimals showing progress between 0 and 1, such as 0.25 when the progress is at 25%?

When I download the files from the server directly to my browser, I get a download progress bar in my browser, so I'm pretty sure the server is reporting the size of the file in some manner.

Here is my code for reporting progress:

    progress: function(progress) { 

        console.log("Dropbox Progress", progress * 100);

    }

Thanks for the help!