Are you exporting the "Project" field by any chance?
If so, can you try to export without it and let us know if that helps?
We have run into similar issue and we removed the project field and it worked.
Just a background
we tried similar export with project field included for a different user and it worked fine.
However with a particular user it failed continuously until we removed the project field.
Can you explain why Please?
Retrieving data ...