In order to show a real time display, GoCube uses the Bluetooth channel (mainly to transmit the cube's state and orientation). If other Bluetooth devices are connected, the sync may be delayed.
The ways to solve/improve this issue are:
1. If possible, make sure GoCube is the only connected Bluetooth device while being used.
2. You can try to turn off the 3D tracking sensor (in the "Hamburger menu", on the top left corner of the app). This will reduce the required bandwidth of GoCube, and will let you play with other Bluetooth devices connected at the same time.