Broken test?

I would like to give some feedback about ...

From: http://www.checkio.org/mission/most-wanted-letter/solve/

HTTP_USER_AGENT:

Mozilla/5.0 (X11; Fedora; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.89 Safari/537.36

If I run the test manually, either using "try it" or in my local IDE, it my code returns the correct result, "m". The "run and test" function returns failure, that my code returns "00000000000000"

Thanks, Matthew