The data on Groups page is behind only by a maximum of 2-3 minutes. If you are connected to the Internet and the local data is synced to the cloud, your Groups page will be updated after your exercise data gets processed which takes a few minutes.
1) Make sure you are connected to WiFi, and that you have a good signal.
2) If you are not using your WiFi, please make sure you enable mobile data on your phone.
3) If those don't work, please make sure you close all other active apps, open the Cubii app and wait for a few minutes.