You have to type something every few minutes to keep it alive. And make the agent do the same, or else you'll get kicked out for your (or DL agent's) lack of activity. Also go to another page every few minutes or reload the page you are on, not just update the chat window, otherwise it will log you out, yes, as it doesn't see chat as you being active on the site.

Clearly no real live person has tested it. It's there, it works, but you have to know how to work it.

The same thing is also available on the phone. That goes via SMS. You can use the DL app and do the same thing over phone. Then you don't worry about being kicked out due to timeout. So if you don't mind typing on your phone, you can do that as well.