[Hummingbird] Hummingbird not minifying JS

I have tried to minify JS with hummingbird, it's put the JS on the WPMU CDN, but it doesn't seem to have minimised the files. An example is: https://hb-minify-juc1ugur1qwqqqo4.stackpathdns.com/www.dorsetcoastalcottages.com/c3454075-e3cd-420e-92c5-5f8f1ab9e991.js