I am watching the network traffic in the Chrome Developer Tool on a page by page load.
I think the best way to explain this is showing it in real time, heres a video
The wpengine support team gave me the following notes to share..
"Based on that argument and the "po_data" function. It looks like it's the PopOver plugin. Unless there is a feature in that plugin that can be set to not make that call back request every time, you'll most likely be better off finding a different solution to display your Pop Up content.
And just to help out further. Here are the lines of code in that plugin that was calling po_data:
774: jsonpCallback: 'po_data',
688: $data = get_user_meta( get_current_user_id(), 'po_data', true );
704: $data = get_user_meta( get_current_user_id(), 'po_data', true );
709: update_user_meta( get_current_user_id(), 'po_data', $data );
402: echo 'po_data(' . json_encode( $data ) . ')';
So, Im not sure if this is something that can be resolved.. We currently have over 60 audio and videos using the Pop Up plugin.. itd be a great effort to move on from this plugin.. but if that needs to happen to get the page load speed down then it is what it is..
Thanks for your time on this.. Look forward to your advice..