setHeaderBufferSize(16384) should be called on all 3 connectors - http, ajp, and https. Otherwise the default 4096 is used which limits GET requests and therefore the number of reports that can be displayed at once. With 75 or so reports the select all and graph workflow generates a 413 error from Jetty and the browser displays a blank page. This fix has been tested locally and succesfully resolves the issue.
Apparently this fix was applied to the AJP connector but neither of the other connectors. Recommendation is to increase the AJP limit and set the http and ssl buffers to 16k.