Failed to load resource: net::ERR_NETWORK_IO_SUSPENDED

Just summarizing my comments under the question for community.

After some testing, it seems, that setting Ajax timeouts for every call is a must. Without timeouts, NET:: errors such as ERR_NETWORK_IO_SUSPENDED, ERR_INTERNET_DISCONNECTED, etc will cause Ajax to stop execution, and would not resume after computer wake up.

For jQuery:

$.ajax({
   url: yourURL,
   timeout: 4000
});

For XMLHttpRequest (XHR):

 xhr.timeout = 4000;

Moreover, an exception handler is necessary for your script to catch connection errors, so that your JavaScript code would not break down because of unexpected behavior/values.

Even with timeouts and exeption handler, your application will throw NET:: errors, but they would not harm your application; you could think of them as Notices.