find where the distribution is different

As per MSDN,this feature is enabled by default, is in preview and should be available when you are not using either:
DirectQuery
Live connect
On-premises Reporting Services
Embedding

or
TopN filters
Measure filters
Non-numeric measures
Use of "Show value as"
Filtered measures - filtered measures are visual level calculations with a specific filter applied (for example, Total Sales for France), and are used on some of hte visuals created by the insights feature

However , This feature surprisingly gets enabled randomly on few reports and not on other, There seems to be no way to turn it off.
This is really confusion to end users.