Appointment admin-ajax.php issue causing appointment time slots not to regenerate

Dear Support,

Short Version:
Clicking on a day in the calendar does not refresh the time slots available for that day in the table on the right.

Long Version:
The issue of the time slots appearing frozen appeared after trying to change the <h3> tags and title in the short code. (this is possibly just a co-incidence).

I looked at the server error logs and then the errors within the browser and noted the following:

GET /alliedhealth/wp-admin/admin-ajax.php?callback=po_data&orig_request_uri=%2Falliedhealth%2Fjohn-muller%2F%3Fwcalendar%3D1448928000&action=inc_popup&do=get_data&thefrom=eludehcs_ppa%230008298441%3Dradnelacw%3F%2Frellum-nhoj%2Fhtlaehdeilla%2Fmoc.94b10e%2F%2F%3Aptth&thereferrer=%2Frellum-nhoj%2Fhtlaehdeilla%2Fmoc.94b10e%2F%2F%3Aptth&_=1446634004423 HTTP/1.1
Connection: keep-alive
Cache-Control: max-age=0
Accept: text/javascript, application/javascript, application/ecmascript, application/x-ecmascript, */*; q=0.01
X-Requested-With: XMLHttpRequest
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.80 Safari/537.36
Accept-Encoding: gzip, deflate, sdch
Accept-Language: en-US,en;q=0.8
Cookie: PHPSESSID=0e1b26fc7d3de9d5c3074d22c15463ac

There is no caching turned on whatsoever throughout the server.

Annoyingly I have the same elements in the original alliedhealth/make-an-appointment/ page it it works fine there.

So it works fine at but fails at

I have tested on Chrome, Firefox, Edge and Mobile Safari including clearing out all history. But still no success.

I have granted support access in the background.

Any guidance would be appreciated.
Kind regards,