The image was so small that I couldn't read what was written. Since it does not seem to be a simple error, it would be better to share the zipped project with you.
Viewing post in WithThreeJS Extension for GDevelop comments
Download to the project file : https://www.mediafire.com/file/xzg8gou04gk1rvp/My_project40.zip/file
I tried to create a 3D model in the second scene