ArcGIS Pro 2.7 API Reference Guide
RefreshMapSeries Method
Example 

ArcGIS.Desktop.Layouts Namespace > Layout Class : RefreshMapSeries Method
Refreshes the map series when the related map data changes. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
public void RefreshMapSeries()
Public Sub RefreshMapSeries() 
Exceptions
ExceptionDescription
This method must be called within the lambda passed to QueuedTask.Run.
Remarks

Refreshing simply re-creates the pages using the current map series parameters. You will want to refresh if one of the following occurs after creating a map series:

1) Features were added to or deleted from the index layer.

2) Edits were made to the sort field or name field values

3) Edit were made to any field being used by the map series for an index feature that's driving the current geographic extent.

Example
//Refresh the map series associated with the layout.

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  layout.RefreshMapSeries();
});
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

Layout Class
Layout Members