Earlier, I reported on digital glitches in detail using the Apple Community website. The original topic is located at Digital blocky glitches/artifacts appear in some resulting HEVC videos after using the Multi-pass option or Encoder type: Slower in Compressor.
Current specs: 16″ MacBook Pro with Apple M4 Pro, macOS Tahoe 26.0.1, Final Cut Pro 11.2, Compressor 4.11.1
The problem still exists, and several open Apple cases have not helped. But I got more info from personal experience, and it looks like such glitches are triggered with specific macOS updates. For instance, I experienced problems with resulting videos on macOS 15.5-15.6.1, then I upgraded to macOS 26.0, and the glitches suddenly disappeared. Everything was good on 26.0.1 as well. But version 26.1 returned the glitches.
So, I noticed an interrelation, and just installed macOS 26.0.1 back. I have not observed any problems since then.
Did someone experience the same issue? Do you know more about what exactly can cause it?
All-in-all, if you work with media files, better to create backups before updating to newer versions of macOS. Just in case. And if you notice digital blocky glitches/artifacts, get back to older versions of Apple software.
