BUG? Springrain Set not in API Data

The Starter-Gear my Druid is wearing, is not in the API Data and even not visibile in the Armory.

But it is still in game. I found the Items on wowhead.
Example: https://www.wowhead.com/item=170624

In the Profile API in the Endpoint Character the Items are listed but not in the Game Data API in the item Endpoint or the media/item Endpoint.