### 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.used_depth_texture) {
		RENDER_TIMESTAMP("Copy Depth Texture");
		
		_render_buffers_copy_depth_texture(p_render_data);
	}
	RENDER_TIMESTAMP("Render 3D Transparent Pass");
	RD::get_singleton()->draw_command_begin_label("Render 3D Transparent Pass");
	rp_uniform_set = _setup_render_pass_uniform_set(RENDER_LIST_ALPHA, p_render_data, radiance_texture, true);
	_setup_environment(p_render_data, is_reflection_probe, screen_size, !is_reflection_probe, p_default_bg_color, false);
	{
		uint32_t transparent_color_pass_flags = (color_pass_flags | COLOR_PASS_FLAG_TRANSPARENT) & ~(COLOR_PASS_FLAG_SEPARATE_SPECULAR);
		RID alpha_framebuffer = rb_data.is_valid() ? rb_data->get_color_pass_fb(transparent_color_pass_flags) : color_only_framebuffer;
		RenderListParameters render_list_params(render_list[RENDER_LIST_ALPHA].elements.ptr(), render_list[RENDER_LIST_ALPHA].element_info.ptr(), render_list[RENDER_LIST_ALPHA].elements.size(), false, PASS_MODE_COLOR, transparent_color_pass_flags, rb_data.is_null(), p_render_data->directional_light_soft_shadows, rp_uniform_set, get_debug_draw_mode() == RS::VIEWPORT_DEBUG_DRAW_WIREFRAME, Vector2(), p_render_data->scene_data->lod_distance_multiplier, p_render_data->scene_data->screen_mesh_lod_threshold, p_render_data->scene_data->view_count);
		_render_list_with_threads(&render_list_params, alpha_framebuffer, can_continue_color ? RD::INITIAL_ACTION_CONTINUE : RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_READ, can_continue_depth ? RD::INITIAL_ACTION_CONTINUE : RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_READ);
	}
	RD::get_singleton()->draw_command_end_label();
	RENDER_TIMESTAMP("Resolve");
	RD::get_singleton()->draw_command_begin_label("Resolve");
	if (rb_data.is_valid() && rb->get_msaa_3d() != RS::VIEWPORT_MSAA_DISABLED) {
		for (uint32_t v = 0; v < rb->get_view_count(); v++) {
			RD::get_singleton()->texture_resolve_multisample(rb_data->get_color_msaa(v), rb->get_internal_texture(v));
			resolve_effects->resolve_depth(rb_data->get_depth_msaa(v), rb->get_depth_texture(v), rb->get_internal_size(), texture_multisamples[rb->get_msaa_3d()]);
		}
		if (taa && rb->get_use_taa()) {
			taa->msaa_resolve(rb);
		}
	}
	RD::get_singleton()->draw_command_end_label();
	RD::get_singleton()->draw_command_begin_label("Copy framebuffer for SSIL");