The website that the desktop app of TheBrain 10 syncs to is api.thebrain.com and not app.thebrain.com . The website that humans access is app.thebrain.com . These are 2 different URLs, and are meant to be different.
The difference is just in the way that these are accessed. They are the same site, and have the same data, but have different ways of processing data.
In short, these are not interchangeable. The endpoint in the desktop app needs to point to api.thebrain.com , and users (you, me, anyone who doesn't speak binary) should use app.thebrain.com to access V9/10 Brains.