When you project cannot reach the Internet, data is written to a local file. When a session is run and internet is available, the contents of this file will automatically upload in the background. This works between sessions, so you can freely start more sessions even when offline.
In Edit->Project Settings->CognitiveVR, you can change the Cache Size. If more session data is recorded and the cache doesn't have enough space allocated, the most recent session data may be lost.
Where is the cache located?
The local data cache is in the Config folder. This is different for each platform. This has been tested on Windows and Oculus Quest 2.
When is data read from the cache?
The data from the cache is read and removed when you have an internet connection and while running the application.