Model Release - 3D created model

Yep, you have been given solid answers here. Sounds like you are doing a great job with the images if they are photo-realistic. You must submit a property release for this type of content. Since you are both the contributor and the intellectual property owner you must sign the property release as both the artist and property owner. It should be relatively quick and painless to attach a release using an Adobe Sign release generated in the portal. Simply email it to yourself, click to sign and then repeat. 

Thanks,

Mat Hayward 

Model Release or Property Release?  Two different things. 

3D assets require you to sign a Property Release attesting that you are the artist and rightful owner of the artwork.  See links below.

https://helpx.adobe.com/stock/contributor/help/property-release.html

https://helpx.adobe.com/stock/contributor/help/terminology-and-importance-of-copyright.html

Did your description (for customers) make it absolutely clear that these are renders? This is important, especially for photorealistic work, as many customers need to know which one they are licensing. In this case it might also help the moderator.