There are several reasons you may see data discrepancies. Here are a few of the most comman:
Different adblockers block different sets of tools. Some adblockers are also configurable and allow a user to customize what destinations they send data to.
If you are concerned about adblockers contact email@example.com and we can walk you through several ways to address the impact of adblockers.
Different tools use different methods to recognize bots. Tools will usually not count users it thinks to be bots in any numbers provided. Because of this, different tools thinking different users are bots can lead to data discrepancies across tools.