### 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
switch (p_params->pass_mode) {
#define VALID_FLAG_COMBINATION(f)                                                                                             \
	case f: {                                                                                                                 \
		_render_list_template<PASS_MODE_COLOR, f>(p_draw_list, p_framebuffer_Format, p_params, p_from_element, p_to_element); \
	} break;
		case PASS_MODE_COLOR: {
			switch (p_params->color_pass_flags) {
				VALID_FLAG_COMBINATION(0);
				VALID_FLAG_COMBINATION(COLOR_PASS_FLAG_TRANSPARENT);
				VALID_FLAG_COMBINATION(COLOR_PASS_FLAG_TRANSPARENT | COLOR_PASS_FLAG_MULTIVIEW);
				VALID_FLAG_COMBINATION(COLOR_PASS_FLAG_TRANSPARENT | COLOR_PASS_FLAG_MOTION_VECTORS);
				VALID_FLAG_COMBINATION(COLOR_PASS_FLAG_SEPARATE_SPECULAR);
				VALID_FLAG_COMBINATION(COLOR_PASS_FLAG_SEPARATE_SPECULAR | COLOR_PASS_FLAG_MULTIVIEW);
				VALID_FLAG_COMBINATION(COLOR_PASS_FLAG_SEPARATE_SPECULAR | COLOR_PASS_FLAG_MOTION_VECTORS);
				VALID_FLAG_COMBINATION(COLOR_PASS_FLAG_MULTIVIEW);
				VALID_FLAG_COMBINATION(COLOR_PASS_FLAG_MULTIVIEW | COLOR_PASS_FLAG_MOTION_VECTORS);
				VALID_FLAG_COMBINATION(COLOR_PASS_FLAG_MOTION_VECTORS);
				default: {
					ERR_FAIL_MSG("Invalid color pass flag combination " + itos(p_params->color_pass_flags));
				}
			}
		} break;
		case PASS_MODE_SHADOW: {