### 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
if (scene_state.instance_data[p_render_list].size() > 0) {
		if (scene_state.instance_buffer[p_render_list] == RID() || scene_state.instance_buffer_size[p_render_list] < scene_state.instance_data[p_render_list].size()) {
			if (scene_state.instance_buffer[p_render_list] != RID()) {
				RD::get_singleton()->free(scene_state.instance_buffer[p_render_list]);
			}
			uint32_t new_size = nearest_power_of_2_templated(MAX(uint64_t(INSTANCE_DATA_BUFFER_MIN_SIZE), scene_state.instance_data[p_render_list].size()));
			scene_state.instance_buffer[p_render_list] = RD::get_singleton()->storage_buffer_create(new_size * sizeof(SceneState::InstanceData));
			scene_state.instance_buffer_size[p_render_list] = new_size;
		}
		RD::get_singleton()->buffer_update(scene_state.instance_buffer[p_render_list], 0, sizeof(SceneState::InstanceData) * scene_state.instance_data[p_render_list].size(), scene_state.instance_data[p_render_list].ptr(), RD::BARRIER_MASK_RASTER);
	}
}
void RenderForwardClustered::_fill_instance_data(RenderListType p_render_list, int *p_render_info, uint32_t p_offset, int32_t p_max_elements, bool p_update_buffer) {
	RenderList *rl = &render_list[p_render_list];
	uint32_t element_total = p_max_elements >= 0 ? uint32_t(p_max_elements) : rl->elements.size();
	scene_state.instance_data[p_render_list].resize(p_offset + element_total);
	rl->element_info.resize(p_offset + element_total);
	if (p_render_info) {
		p_render_info[RS::VIEWPORT_RENDER_INFO_OBJECTS_IN_FRAME] += element_total;
	}
	uint64_t frame = RSG::rasterizer->get_frame_number();
	uint32_t repeats = 0;
	GeometryInstanceSurfaceDataCache *prev_surface = nullptr;
	for (uint32_t i = 0; i < element_total; i++) {
		GeometryInstanceSurfaceDataCache *surface = rl->elements[i + p_offset];
		GeometryInstanceForwardClustered *inst = surface->owner;
		SceneState::InstanceData &instance_data = scene_state.instance_data[p_render_list][i + p_offset];
		if (inst->prev_transform_dirty && frame > inst->prev_transform_change_frame + 1 && inst->prev_transform_change_frame) {
			inst->prev_transform = inst->transform;
			inst->prev_transform_dirty = false;