Using a Persistent stream key is BAD security, and not something I'd recommend using, in most cases
Facebook has recently been making undocumented changes to live streaming, at least as far as I've noticed in /Live/Producer. Going live, especially for Scheduled Videos, which I use so non-Facebook users can also watch, has changed a little. There are new required fields, and additional steps. And I ran into an issue last month, for a few weeks running where Scheduled Videos wouldn't start automatically as they used to. They do auto start now, but about 10 seconds late, vs right on time as was the case last year... odd... the joy of using a free service