Hey the first image is the union, that is how it is supposed to look, the second image is the mesh, and they are not lining up. I noticed the orientation was different for some reason if that helps
Once I am done with the build in studio, I union it and export, then import it back as an obj. I just create a meshpart in workspace and import the obj there
Honestly just looks like the rotation is off by a degree or two. Have you looked at the mesh’s map position compared to the union’s?
If that isn’t it, it’s possible your mesh is being resized by the client when you import it in, which happens automatically. Like before, just compare its map position and rotation properties in relation to the union.
If anything’s different, just manually input what it should be through the explorer.