I have multiple sanctions on my account for the same issue, all of which are errors created by the automated system for uploading UEFN creations.
No human being has actually inspected my island, as the sanctions were activated immediately upon me submitting my island for review.
The system is detecting is that my island violates your IP Ownership rule. This is factually untrue; everything in my island is an original creation to the best of my knowledge. I can provide proof upon request.
If I knew what was causing the error I would fix it immediately. Because of this glitch, I am unable to update my island and push new public releases.
As of now, my sanction appeals have also been ignored.