Artifacts that randomly creates on MXF exports

Hello,

Sur ma derniere livraison d'environs 60 fichiers. 7 ont été refusé a cause de la presence d'artefact (Digital breakup or Digital hit sur le rapport) Jamais en 8 ans nous avons eu se probleme.

The artifacts are not present in the source files, and when we re-export, the MXF file is OK. The artifacts seem to appear randomly, from one machine to another and from one video to another.

I tried to perform a quality check using QSCAN (qscan.io, apparently widely used in the industry), but it didn't reveal these artifacts, even though they are clearly present in the image.

Any ideas? Please 🙂

Our source files are in Apple ProRes LT format and were exported as MXF OP1a with closed captions.

2 iMacs 20,1 on macOS 15.7

Premiere 25.5 (25.3 before the update)

Attached are three examples; most are 1 frame long, but the last one is 8 frames long.

Sorry for the small images, but they are NSFW.