Premiere creates black artifacts in the preview monitor and final export

The imported footage is clean, without artefacts - 4k h265.

The sequence settings have been copied exactly from the imported footage.

No effects added, no color grading, no filters or LUTs added.

The program monitor then randomly displays flashing black and sometimes colored artifacts, see attachments.

I have already deleted the media cache and changed the renderer - no effect.

When I open the project on another computer, there are no artifacts.

Do you have any ideas? Since the artifacts are also visible in the rendered material, I'm slowly getting a little desperate, as it's particularly noticeable in bright scenes. Thanks in advance!