I'm not a MAC user, but I do know /Live/Producer can be flaky, especially depending on browser. And sometimes it takes a browser refresh to show current status/video preview. On Windows, some features appear with Chrome and not MS Edge (Chromium), for example.
Is OBS giving you a green light indicating connected/streaming at set bit rate?
Have you set your bitrate at reasonable level (like maybe 3000-4000 Kbps, if not lower, as least to initially set up and make sure basics are working)?
IF OBS giving you a green light (sorry, I'm a newbie so don't know what play triangle button is/means) then
- my recommendation would be when setting up Scheduled Live event, make it a test broadcast. Then have someone else set up as Admin of FB page, and then only that 'admin' can see your test stream. See if stream is working even if /Live/Producer isn't showing it to you