Hi Austin,
I cannot reproduce your problem.
I attached the GRC file I used to test. Changing any of the parameter gives me the expected output on my scope.
We had an issue reported lately, that the programs using libiio (this include the GnuRadio blocks) would not work correctly with non-US locales. If you're using a non-US locale, try to export LC_NUMERIC=C before you execute GnuRadio.
Alternatively, you can update libiio to the latest version available in our git repository.
Regards,
Paul