New Relic Support requires additional troubleshooting details about what is happening on the browser side and you are not able to provide either an accessible URL or the source code for your page.
Based on your browser type, create a HAR (HTTP Archive) file for investigation, and send it to support.newrelic.com. The HAR file contains all information about network calls involved with a page during the recorded time period.
When recording the HAR file, use features on your site to generate the appropriate type of activity. For example, if you have AJAX problems, exercise the section of your page that makes AJAX calls.
HAR files capture all network traffic during the time that they are being recorded. This traffic data can include private or personally identifiable information (cookies, passwords, credit card numbers, etc.). Customers are responsible for any data they provide to New Relic, including within HAR files. HAR files can be edited with a text editor. Before sharing a HAR file, we strongly recommend manually removing any sensitive information.