API issue when requesting/using text forecasts

The API request to (http://api.wunderground.com/api/{KEY}/conditions/forecast10day/astronomy/q/24084.json) is incorrectly returning empty result sets for the txt_forecast fields (txt_forecast->dateData->forecastday->day->title,fcttext,fcttext_metric).  However, the same call works for other zip codes, but they too will experience null fields intermittently.

This issue started happening in the last couple of weeks, and happens intermittently.  The API will return data sometimes, other times it will be empty.

Any idea what causes this or a workaround?  See example responses attached in image below

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Thanks!