BTP destination not appearing in BAS storyboard

[rpscg]

I am following this course: Develop Full-Stack Applications Using Productivity Tools in SAP Business Application Studio  and have encountered a problem. The course material is a bit out date with the referenced Cloud systems (also the internal walkthrough playbacks don't match the course screens) , but I have been able to follow it up until the point that it uses live data.

In Course Unit 2, from BAS I have logged into the accelerator hub and obtained service details, which have correctly transferred into a service definition.   

In another section following this, I have to create a destination in BTP cockpit to the same hub.

The connection check gives

I'm not sure if 404 is the correct response but it suggests the server is at least responding. I can also get a feed response from the Hub API "Try Out" feature of the Business Partner API that the service is modelled on, so it would appear that a correctly formed API request would work.

I have a problem with the built Fiori Elements application. The lesson starts off using sample data, which works. I am then prompted to build a 'live data' configuration and this is where things fail. The screen below shows the 'apihub_sandbox' destination being populated in the course article, but in my case it is empty, no default, do dropdown.

It is not explained how this destination is supposed to recognised in BAS or if there is a step missing. I have been back and forth and cannot find any missing steps. I have looked at notes on the property WebIDEUsage and it doesn't list it being used in this way, i.e. I don't know if 'apihub_sandbox' is a new standard value that has a certain use or if it is just an identifying tag value. 

I have the required administrator role in BAS. I have triple-checked the destination properties, but it just doesn't work. 

Can anyone provide any guidance?