When Live Streaming does not appear to be working as expected, especially after it's been working in the past, it is recommended that the first thing to check and verify is the "Stream name/key."
And yes, the YouTube stream name/key has changed without notice in our testing in the past. We do not know when or why Google/YouTube changes these settings but it sure would be nice if they notified users of these changes.
It is encouraged for users to reach out to suppport when you have issues like these. Here are some ways to contact YouTube: https://www.wikihow.com/Contact-YouTube
And you ever get a response, please pass along any useful information.
Tags: live streaming, youtube