Sandbox is not available alongside to academy course

I am doing modelling fundamentals course and sandbox has stop appearing alongside the exercise page. I can login to Sandbox separately to de exercises but 'check database' does not pick those.
What is the problem?

Hi there.

I'm now facing a similar problem.
When I press the "run" button on the sandbox toggle with my cypher script, the prompt area is refreshed and nothing happens.
ShOga_0-1663655096578.png
Is there any setup needed to enable the sandbox or Neo4j DB?

Following are what I tried:
- cleared caches and cookies
- signed out from GraphAcademy and then signed in
- tried other browsers (Chrome and Edge on Windows, and Chrome and Safari on Mac)

Hope you find my question.

The query failed just because the browser is not connected to DB.
After connecting to DB via Neo4j Browser, I am able to run cypher query on sandbox toggle.