1.If the report has more than one page, slice the report by the page(s) that was viewed. "Blank" means either a report page was added within 24 hours of the new page appearing in the slicer list, or report pages have been deleted. "Blank" captures these types of situations.
2.Report Page View depends on network latency, ad blockers, firewalls, and network rules set by your organization, this data may never reach Power BI. Therefore, the performance and Report Page View data may not include all views or all users.
You can refer to the following link:
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