Mubble calculates live data usage.
 
 You could be facing this problem due to any of the following reasons:
 1. We are not showing """"live"""" balance as you expect.  We are calculating wrong data usage.
 2. SIM2 balance going to SIM1. In almost all such cases, We got the balance, but put it on the wrong SIM

This can be happen with some particular device models.
Send  your device details such as device model, android version, mubble app version to care@mubble.in