Duplicate Urls for many terms
There's a setting under the Global Redirect settings to Remove Trailing Zero Argument:



According to the description for this option:


  If enabled, any instance of "/0" will be trimmed from the right of the URL. This stops duplicate pages such as "taxonomy/term/1" and "taxonomy/term/1/0" where 0 is the default depth.


That should fix the problem you're having.