MacStudio M2Ultra glitchy and or incomplete H264 exports

1. Premiere Pro 24.6.0

1. Media Encoder 24.6 (Build 74)

2. Chip: Apple M2 Ultra, Total Number of Cores: 24 (16 performance and 8 efficiency), Memory: 192 GB.

2. Sonoma 14.6.1 (23G93)

2. QNAP NAS mounted via AFP (I get the same error when mounting as SMB)

3. Export / Media / Preset "Match Source - High Bitrate"

Exporting H264 on OSX  is creating glitchy and/or incomplete muxed file without reporting an error either in PPro or AME. I have tried starting in Safe Mode with a new project, writing to the local drive (media also on the local drive) with all options ticked and still receive the same error.  

The media is a mix but is predominately ProRes4444 Arri LogC 4480x3096.

Timeline is HD 1920x1080 ProRes 422(HQ)

I am able to export the timeline by choosing "Match sequence preview settings" - in this case Prores 422(HQ). I can't convert the output to H264 via AME without getting the same glitches. I am able to convert to H264 via AME on a Windows computer on the same network. I am also able to export the same timeline via Davinci Resolve (XML roundtrip) on the MacStudio without glitches.

Any help is greatly appreciated.

Thank you.