SYMPTOM:
The "Matrix of Bar Graphs" visualization and other Flash widgets in Visual Insight are converted to grids when exported to PDF in Strategy Web 9.4.1.
Below, the "Matrix of Bar Graphs" visualization In Visual Insight

After exporting to PDF, this visualization appears as a grid:

CAUSE:
Flash widgets, such as the "Matrix of Bar Graphs" cannot be displayed in PDF, and are therefore converted to a grid.
ACTION:
Change Flash exports from MHT to PDF at the project configuration level as seen in article KB34618: Feature in MicroStrategy Developer 9.x - 10.x: Choose MHT or PDF format to export to Flash.. After the setting is changed, restart the Strategy Web server, then export the dashboard to flash.
MORE INFORMATION:
For a similar issue in Report Services Documents, refer to article TNKB44302: After a dashboard exported to PDF, widgets are replaced by graphs or grids in MicroStrategy Web 9.4.1 and newer version.