My workflow is somewhat different from yours (I never use New Inherited Scene), but I sometimes (rarely) have to close the scene and the script before Godot will recognize the reimport. And on some occasions, I have to manually delete the .import file.
I have also had occasion to delete the mesh from my scene (I always create a separate scene where the mesh is a child), and drag the mesh from the filesystem tab to the scene.
I have already tried to close and reopen the scene and also godot.
About the .import file, I haven’t tried to delete it yet, though I can’t find it in my res folder.
Do you know where can I find it?
You can’t see it from within Godot. You have to use your operating system file manager and navigate to the resource folder that contains your scene. You will see the .import file there.