Shortcode works in debug mode but not when debug mode false

I have been having trouble getting this json shortcode to work.

I used this example as a test case:
[json src=”http://developer.yahooapis.com/TimeService/V1/getTime?appid=YahooDemo&output=json” lifetime=”30″]At the tone, the time will be: {Result.Timestamp}[/json]

If I go into wp-config.php and enable debug mode, then it works in both my posts and in the JSON shortcode test tool. However, when I run it with debug mode disabled, then it seems to return nothing where the data should appear (in the example, the complete output would be “At the tone, the time will be:”).

Any suggestion on how to debug this when debug mode is disabled?

https://wordpress.org/plugins/json-data-shortcode/