### Godot version

4.0.2 stable

### System information

issue tested on win10 with ryzen 7 and rx 6600, win11 with ryzen 7 and gtx 3050

### Issue description

When creating a screen reading post processing shader, the normal buffer functions correctly in the editor, but does not seem to be functioning as expected in debug, producing only a solid colour when run. I am unsure if this behaviour is intended, but if so, I feel it should be properly documented.

Running correctly in editor:
![image](https://user-images.githubusercontent.com/71034402/230672620-fc5e4baf-c12e-4755-b7a2-206087459307.png)

Solid colour in debug:
![image](https://user-images.githubusercontent.com/71034402/230672489-d9c29755-c2d3-4e72-9ea0-355148e916fe.png)


### Steps to reproduce

*this shader should be attached to a MeshInstance3D quadmesh*
minimal shader to reproduce:

```glsl
shader_type spatial;
render_mode unshaded, cull_disabled;

uniform sampler2D NORMAL_TEXTURE : hint_normal_roughness_texture, filter_linear_mipmap;

void vertex(){
	VERTEX *= 2.0;
	POSITION = vec4(VERTEX, 1.0);
}

void fragment(){
	ALBEDO = texture(NORMAL_TEXTURE, SCREEN_UV).rgb;
}
```

### Minimal reproduction project

N/A
SceneShaderForwardClustered::MaterialData *material = p_material;
	RendererRD::MaterialStorage *material_storage = RendererRD::MaterialStorage::get_singleton();
	_geometry_instance_add_surface_with_material(ginstance, p_surface, material, p_mat_src.get_local_index(), material_storage->material_get_shader_id(p_mat_src), p_mesh);
	while (material->next_pass.is_valid()) {
		RID next_pass = material->next_pass;
		material = static_cast<SceneShaderForwardClustered::MaterialData *>(material_storage->material_get_data(next_pass, RendererRD::MaterialStorage::SHADER_TYPE_3D));
		if (!material || !material->shader_data->valid) {
			break;
		}
		if (ginstance->data->dirty_dependencies) {
			material_storage->material_update_dependency(next_pass, &ginstance->data->dependency_tracker);
		}
		_geometry_instance_add_surface_with_material(ginstance, p_surface, material, next_pass.get_local_index(), material_storage->material_get_shader_id(next_pass), p_mesh);
	}
}
void RenderForwardClustered::_geometry_instance_add_surface(GeometryInstanceForwardClustered *ginstance, uint32_t p_surface, RID p_material, RID p_mesh) {