### 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
RendererRD::LightStorage *light_storage = RendererRD::LightStorage::get_singleton();
	ERR_FAIL_NULL(p_render_data);
	Ref<RenderSceneBuffersRD> rb = p_render_data->render_buffers;
	ERR_FAIL_COND(rb.is_null());
	Ref<RenderBufferDataForwardClustered> rb_data;
	if (rb->has_custom_data(RB_SCOPE_FORWARD_CLUSTERED)) {
		
		
		rb_data = rb->get_custom_data(RB_SCOPE_FORWARD_CLUSTERED);
	}
	bool is_reflection_probe = p_render_data->reflection_probe.is_valid();
	static const int texture_multisamples[RS::VIEWPORT_MSAA_MAX] = { 1, 2, 4, 8 };
	
	
	RENDER_TIMESTAMP("Prepare 3D Scene");
	
	_update_sdfgi(p_render_data);
	
	for (uint32_t i = 0; i < (uint32_t)p_render_data->voxel_gi_instances->size(); i++) {
		RID voxel_gi_instance = (*p_render_data->voxel_gi_instances)[i];
		gi.voxel_gi_instance_set_render_index(voxel_gi_instance, i);