Render is flashing black

[Jerry 1066]

OK after many renders with the same settings I have one this morning which is flickering with short and long black dropouts. The sound is still there but the visual looks like someone is switching the lights on and off.

I'm using a new Mac Studio M1 Max Ventura 32Gb. As I mentioned, I've rendered out lots of final renders at my current settings but this one has hundreds of black visual dropouts.

The monitor is fine, this has all happened in the final render, and shows up whichever media player I use to play it. My older renders are still playing OK though.

My suspicion is that because the original video is essentially a close-up of running water with a lot of movement going on, the (phantom on a Mac Studio) GPU couldn't handle it. Yet it plays back at full resolution during editing no problem.

Must say I am *very suspicious* of the Mac Studio embedded GPU, half of my Photoshop files open as plain black, or scrambled, and Photoshop itself is stuffed with visual artefacts.

But anyway, thoughts on the flashing black in my render?

[Jerry 1066]

Screen recording of render playing attached

[Peru Bob]

Have you tried restarting the computer to see if the issue recurs?

[Jerry 1066]

Yes I have just restarted the Mac and re-rendered the project and had the identical issue. I have also saved the project under a different name to see if that helped but every render is coming out flashing black.