### Godot version

v4.0.beta17.official [c40020513]

### System information

Windows 11, OpenGL (Compatibility), RTX 2060 (31.0.15.2824)

### Issue description

I tried to make a blurred panel for a ui element with texturelod via shader:

```glsl
shader_type canvas_item;

uniform sampler2D SCREEN_TEXTURE : hint_screen_texture, filter_linear_mipmap_anisotropic;
uniform float blur_amount : hint_range(0.0, 5.0);

void fragment() {
	vec4 blurred = textureLod(SCREEN_TEXTURE, SCREEN_UV, blur_amount);
	COLOR = blurred;
}
```

but what I got instead is this:
![image](https://user-images.githubusercontent.com/72286622/217170426-49f6712d-47ef-4c53-b9f1-30d8ad868084.png)

vulkan renderer does not exhibit this issue:
![image](https://user-images.githubusercontent.com/72286622/217170565-a013c712-94f6-49d1-b9ec-091c28a7790b.png)


### Steps to reproduce

1. Add a TextureRect node
2. Add a Panel node to overlay the previously added node
3. Apply the blur shader to the panel node

### Minimal reproduction project

N/A
break; 
							}
						}
					}
					if (height < best_height) {
						best_height = height;
						best_idx = j;
					}
				}
				
				for (int k = 0; k < si.size.width; k++) {
					v_offsets[k + best_idx] = best_height + si.size.height;
				}
				si.pos.x = best_idx;
				si.pos.y = best_height;
				if (si.pos.y + si.size.height > max_height) {
					max_height = si.pos.y + si.size.height;
				}
			}
			if (max_height <= base_size * 2) {
				atlas_height = max_height;
				break; 
			}
			base_size *= 2;
		}
		texture_atlas.size.width = base_size * border;
		texture_atlas.size.height = nearest_power_of_2_templated(atlas_height * border);
		for (int i = 0; i < item_count; i++) {
			TextureAtlas::Texture *t = texture_atlas.textures.getptr(items[i].texture);
			t->uv_rect.position = items[i].pos * border + Vector2i(border / 2, border / 2);