### 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
while (geometry_instance_dirty_list.first()) {
		_geometry_instance_update(geometry_instance_dirty_list.first()->self());
	}
}
void RenderForwardClustered::_geometry_instance_dependency_changed(Dependency::DependencyChangedNotification p_notification, DependencyTracker *p_tracker) {
	switch (p_notification) {
		case Dependency::DEPENDENCY_CHANGED_MATERIAL:
		case Dependency::DEPENDENCY_CHANGED_MESH:
		case Dependency::DEPENDENCY_CHANGED_PARTICLES:
		case Dependency::DEPENDENCY_CHANGED_MULTIMESH:
		case Dependency::DEPENDENCY_CHANGED_SKELETON_DATA: {
			static_cast<RenderGeometryInstance *>(p_tracker->userdata)->_mark_dirty();
			static_cast<GeometryInstanceForwardClustered *>(p_tracker->userdata)->data->dirty_dependencies = true;
		} break;
		case Dependency::DEPENDENCY_CHANGED_MULTIMESH_VISIBLE_INSTANCES: {
			GeometryInstanceForwardClustered *ginstance = static_cast<GeometryInstanceForwardClustered *>(p_tracker->userdata);
			if (ginstance->data->base_type == RS::INSTANCE_MULTIMESH) {
				ginstance->instance_count = RendererRD::MeshStorage::get_singleton()->multimesh_get_instances_to_draw(ginstance->data->base);
			}
		} break;
		default: {
			
		} break;
	}
}
void RenderForwardClustered::_geometry_instance_dependency_deleted(const RID &p_dependency, DependencyTracker *p_tracker) {
	static_cast<RenderGeometryInstance *>(p_tracker->userdata)->_mark_dirty();
	static_cast<GeometryInstanceForwardClustered *>(p_tracker->userdata)->data->dirty_dependencies = true;
}
RenderGeometryInstance *RenderForwardClustered::geometry_instance_create(RID p_base) {