We are currently experiencing issue with the statistics calculation for the opened email. The opens calculation is lagging for few hours from the actual event, and this affects the display for open events.
This issue only affects the reporting for opens that are being displayed for user interface, the telemetry data and tracking themselves are working normally. Other functionalities such as app access and email sending are not affected by this issue and should work as usual.
We are still investigating this issue and will give an update about the progress.