Download link parse error after replacing mp3

After testing the podcast plugin with an example mp3 file, I updated some of the podcast page and replaced the audio – so the filesize is different.

I can’t seem to re-trigger the auto-generation of the filesize for the page because when viewed in Safari on MacOS, The browser gives the an error “cannot parse response” – Both Chrome and Safari think they are downloading 156MB (size of the old mp3), but the actual file size seems to be 132.2 MB (new mp3)

Any ideas how I can make sure all the right bits of information are correct?

The page I need help with: [log in to see the link]