Update to MacOS 27.0 breaks Streaming / BBC iPlayer / YouTube playback.

Try this

If your M1 Mac Mini is connected to an external display via HDMI or DisplayPort, macOS 27 has a specific bug that breaks video playback when audio is routed to certain primary monitors.

• Open System Settings and go to Sound.
• Under the Output tab, temporarily switch your sound output away from your main monitor (e.g., switch to Mac Mini Speakers, a secondary monitor, or a pair of headphones).
• Test a YouTube or BBC iPlayer video to see if playback immediately resumes. 

For me, on another Mac type, video playback is working just fine

I found the fix for this in my case with LG monitors. AI (ChatGPT) told me Apple's documentation on macOS 27 (maybe updated docs) says:

1. Open the Audio MIDI Setup app.
2. Select the sound output you're having a problem with.
3. Check the format and change it if it's set wrong. The setting there can be corrupted during upgrade.

In my case, it was set to what I've seen other Mac users' settings were set to, "2 ch 24-bit Integer 48.0 kHz". I changed it to "2 ch 16-bit Integer" and the sound output started working again. I changed it back to what it was set to originally, and it still worked. So, I don't know why, but I assumed something got corrupted and that just overwrote the corrupted setting to fix it.

BUT, today it stopped working again, two days after I fixed it this way. I went and did the same things, it looked the same way, and it was fixed exactly the same as before. So, I assume there will be many, many updates coming for macOS 27 to fix bugs like this.

M2 studio, fighting this for a while, midi adj MIDI Audio configuration and change audio frequency format to whatever is not 48 kHz. Pick 44, 88 or 96. And it works(from Reddit), also turn monitor off and on works, I had tried a reinstall of 27 not fixed, await patch

Had the same issue, Streaming don't play, locally stored QT videos don't play, switching to the Mac mini (M1) speakers worked for me, videos play.

However why this would happen at all is pretty bad, I just updated to 27.0.1, did not help.

I hope Apple can fix this soon, don't want to listen through the small tinny speaker.

• I'm using a secondary display through the HDMI port

Wow, it took me a while thinking it was the streaming service, then I saw it happened with all services, and not on other devices. So a quick search took me here.

I have multiple computers that I connect to my monitor, so by using the monitor audio output to go to my speakers, allows which ever computer video input I have selected will get the audio as well.

This is a very silly bug and I hope it is fixed in the next update.

Update,

I reinstalled Goden Gate

• did not change

My mac did a couple of "strange" reboots before I could log in

• Still videos would not play

Several hours later I shut down my Mac mini, after I started it again, videos play and everything is as it was before.

I don't know what fixed it

Further to the os27 2 external monitors fault/problem

Sound alert stops working if you move from internal Mac speaker and will not work until restart the coloured spinning wheel appears when fault occurs 

Further to the os27, 2 external monitors fault/problem

Sound alert stops working if you move from internal Mac speaker and will not work until restart, the coloured spinning wheel appears when fault occurs 

I have same system, but with the M2 and having the same issue. My audio is already going through the Mac mini speakers.