3rd party location is highest in priority but default location is still selected

[Tondevries]

Hi All, 

We have installed a 3rd party app as location. This can't be selected as default location, so as a work around we have assigned products to that location via the multiple location option. 

Also our 3rd party app is highest in priority. But still new orders are giving the default location instead of the 3rd party app. Even if the default location is not assigned to the product. 

FE: Prouduct 1 is assigned to Location 3rd party app as only location. It has stock. But when order comes in it still gets the default location and we have to manually adjust the location to the 3rd party app. 

Hope you can help!