I have the prompt but it says that there is a connection error and the very same old sandbox URL is displayed. It doesn't sync with the new one the system creates or that I create. I 've tried a lot of configurations of combination of terminating/not terminating the sandbox, logging in and out, waiting between the step, etc. It looks like a lot of people are experiencing various issues with the sandbox.
EDIT:
Looks like it works now. Hopefully it will continue to work until the end of the cours
All I can say (for now) is to be patient! Here is what happens.
When you enroll in a course, a sandbox instance is requested. At the sandbox site, if there is an instance in the pool, it grabs it and initializes it with the data required for the course. This will result in the $neo4j prompt within a minute or so. If, however, there are no sandbox instances in the pool, the sandbox site needs to instantiate it which takes longer. Sometimes it takes a couple of minutes to see the $neo4j prompt, unfortunately. We are working on ways to speed this up for GraphAcademy users.