@stjosh that’s a very detailed investigation, thank you! The change you have found only does some modifications to the _pingUrl method, but if you are saying it’s never reached it should not be the cause of the problem.
My current suspicion is there’s something going on in _execute method which has a bit complicated timer handling or this block kicks in before the _execute and removes scheduled job from the queue.
Will try setting up a separate instance and schedule some posts for longer than a day in advance. If you have a chance to add more logs to both recursiveRun and _execute function to give more details that would also be great help! Cheers ;)