This issue is now fixed – when you publish a new video or edit an existing one, settings should be saving correctly. Realtime data in YouTube Analytics is also back on track. So sorry for the frustration here. Thanks for bearing with us while we figured things out.https://twitter.com/TeamYouTube/status/1176645711691010048 …
To start monetizing on YouTube, your channel will need to be eligible and reviewed + approved for the YouTube Partner Program. More about the application process: https://yt.be/help/PHae . Also, this troubleshooter can help you set up an AdSense account: https://yt.be/help/Ta2D