I can confirm that the add-on appears to be working fine on your site at this time.
Your ISP/gateway might be doing something weird to the response. Can you dump the response and look at it? It should be JSON, but if upstream from your device is mangling the response who knows what it could look like.
<script defer src="/myjsfile_1.js"></script> <script defer src="/myjsfile_2.js"></script> <script defer src="/myjsfile_3.js"></script>