Thanks for the report, Patrick!
The UX designer from Print Studio, Leslie, writes:
"I believe the issue is actually with the stl file format not being able to be written out with the repairs (I would have to check with our dev team). If you can advise customers to use (The brand new!) File>Save instead of export and reimport this would address the problem. Export and re-import of .stl should really be avoided."
Let me know if that solves your issue.