cURL通过PHP返回不完整的页面内容

I'm trying to scrape data from (train locations in real time) http://italoinviaggio.italotreno.it/SiteCore/IT/italo/Pagine/default.aspx via php

When visiting the page directly with a browser the results are as follows (excerpt)

<option value="6776">35915</option>
<option value="9968">9968</option>
<option value="6777">35918</option>
<option value="6965">35922</option>
<option value="9973">9973</option>

When using either cURL or file_get_contents("http://...") the returned results are as follows (excerpt)

<option value="6776"></option>
<option value="9968"></option>
<option value="6777"></option>
<option value="6965"></option>
<option value="9973"></option>

Please note the following

• Chrome Dev tools show no XHRs
• The page loaded in a browser works correctly even with JS disabled
• Chrome Dev tools show no Flash or any other "extra" components being downloaded outside of JS HTML and CSS

Can somebody please explain to me how it's possible?

Is it some magical aspx feature?