### 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
ERR_FAIL_COND_V(image->is_empty(), Ref<Image>());
	if (texture->format != texture->real_format) {
		image->convert(texture->format);
	}
#else
	Vector<uint8_t> data;
	
	int data_size = Image::get_image_data_size(texture->alloc_width, texture->alloc_height, Image::FORMAT_RGBA8, false);
	data.resize(data_size * 2); 
	uint8_t *w = data.ptrw();
	GLuint temp_framebuffer;
	glGenFramebuffers(1, &temp_framebuffer);
	GLuint temp_color_texture;
	glGenTextures(1, &temp_color_texture);
	glBindFramebuffer(GL_FRAMEBUFFER, temp_framebuffer);
	glBindTexture(GL_TEXTURE_2D, temp_color_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture->alloc_width, texture->alloc_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, temp_color_texture, 0);
	glDepthMask(GL_FALSE);
	glDisable(GL_DEPTH_TEST);
	glDisable(GL_CULL_FACE);
	glDisable(GL_BLEND);
	glDepthFunc(GL_LEQUAL);
	glColorMask(1, 1, 1, 1);
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D, texture->tex_id);
	glViewport(0, 0, texture->alloc_width, texture->alloc_height);
	glClearColor(0.0, 0.0, 0.0, 0.0);