It is considered normal and you may see some discrepancy between Reportei report information and Facebook Insigths. =) Always remember to select the same time period in both the report and Facebook when comparing.
The data displayed in Facebook Insights and the API data does not always seem to be fully synchronized. In some cases, the API may send us some data that differs from Facebook Insights, but Reportei depends directly on the API. So some minor discrepancies in the metrics may appear from time to time and are not cause for concern.
Important: Even generating a report that analyzes to the present day, the data can and will vary. Social networks are always processing and updating information. The report, on the other hand, is only a “portrait” of a moment. So it is important to consider this if you are comparing report data with data presented in the social network interface.