my image rejected due generated by AI and not labelled as such.

Most 3D images are confused for AI. 

Blender is not an AI software, but it can now use AI through third-party plugins & external tools. Make sure you’re not using any such tools.

Submit a signed Property Release Form by you as the artist who created it. If this happens again, you can reference your Property Release form on file.

https://helpx.adobe.com/stock/contributor/content-policies-guidelines/model-property-releases/property-release-overview.html

Hope that helps.

Appeal! Let Adobe know that there moderation is making mistakes.

How to appeal a false rejection of "Missing Generative AI Flag." | Community

There is an inquiry form at the bottom of the contributor page.
Since you cannot attach files directly to the form, I suggest uploading them to cloud storage and sharing the link.

https://contributor.stock.adobe.com/contact

Please submit your inquiry via the contributor page.
Providing a screenshot of the Blender workspace may help streamline the process.