### 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
RD::FramebufferFormatID fb_format = RD::get_singleton()->framebuffer_get_format(p_framebuffer);
	p_params->framebuffer_format = fb_format;
	if ((uint32_t)p_params->element_count > render_list_thread_threshold && false) { 
		
		thread_draw_lists.resize(WorkerThreadPool::get_singleton()->get_thread_count());
		RD::get_singleton()->draw_list_begin_split(p_framebuffer, thread_draw_lists.size(), thread_draw_lists.ptr(), p_initial_color_action, p_final_color_action, p_initial_depth_action, p_final_depth_action, p_clear_color_values, p_clear_depth, p_clear_stencil, p_region, p_storage_textures);
		WorkerThreadPool::GroupID group_task = WorkerThreadPool::get_singleton()->add_template_group_task(this, &RenderForwardClustered::_render_list_thread_function, p_params, thread_draw_lists.size(), -1, true, SNAME("ForwardClusteredRenderList"));
		WorkerThreadPool::get_singleton()->wait_for_group_task_completion(group_task);
		RD::get_singleton()->draw_list_end(p_params->barrier);
	} else {
		
		RD::DrawListID draw_list = RD::get_singleton()->draw_list_begin(p_framebuffer, p_initial_color_action, p_final_color_action, p_initial_depth_action, p_final_depth_action, p_clear_color_values, p_clear_depth, p_clear_stencil, p_region, p_storage_textures);
		_render_list(draw_list, fb_format, p_params, 0, p_params->element_count);
		RD::get_singleton()->draw_list_end(p_params->barrier);
	}
}
void RenderForwardClustered::_setup_environment(const RenderDataRD *p_render_data, bool p_no_fog, const Size2i &p_screen_size, bool p_flip_y, const Color &p_default_bg_color, bool p_opaque_render_buffers, bool p_pancake_shadows, int p_index) {
	RendererRD::LightStorage *light_storage = RendererRD::LightStorage::get_singleton();
	Ref<RenderSceneBuffersRD> rd = p_render_data->render_buffers;
	RID env = is_environment(p_render_data->environment) ? p_render_data->environment : RID();
	RID reflection_probe_instance = p_render_data->reflection_probe.is_valid() ? light_storage->reflection_probe_instance_get_probe(p_render_data->reflection_probe) : RID();
	
	if (p_index >= (int)scene_state.uniform_buffers.size()) {
		uint32_t from = scene_state.uniform_buffers.size();
		scene_state.uniform_buffers.resize(p_index + 1);
		for (uint32_t i = from; i < scene_state.uniform_buffers.size(); i++) {