In my case it was also a consistency issue and unpredictable system behavior: I plugged in to the method for some custom processing and noticed that my plugin is called twice for the same data.
@mage2pro
Could you please add the description of steps, actual result and expected result to this ticket?
It will help other community members to find this problem when they use GitHub, which is, unfortunately, impossible when the full description is placed on the external resource.