### Godot version

4.1.1 stable

### System information

Windows 10

### Issue description

this is the default size loaded on startup 1024 which seems fine but it actually have loaded the default [2048] and ignored the size in project settings
![image](https://github.com/godotengine/godot/assets/53877170/c8c71de7-468a-487f-8e6c-dba1ce0f8fa5)

changing it now to any size will break it 
[2048]
![image](https://github.com/godotengine/godot/assets/53877170/3082ff09-b7d7-41f7-8fbb-813074a54135)

[512]
![image](https://github.com/godotengine/godot/assets/53877170/5ea4620f-52b5-4d0e-a5f5-747e777cd59d)


### Steps to reproduce

change 2d shadow atlas size in project settings while using compatibility renderer. 

### Minimal reproduction project

_
uint32_t instance_buffer_index = 0;
		RID tex;
		RS::CanvasItemTextureFilter filter = RS::CANVAS_ITEM_TEXTURE_FILTER_MAX;
		RS::CanvasItemTextureRepeat repeat = RS::CANVAS_ITEM_TEXTURE_REPEAT_MAX;
		GLES3::CanvasShaderData::BlendMode blend_mode = GLES3::CanvasShaderData::BLEND_MODE_MIX;
		Color blend_color = Color(1.0, 1.0, 1.0, 1.0);
		Item *clip = nullptr;
		RID material;
		GLES3::CanvasMaterialData *material_data = nullptr;
		CanvasShaderGLES3::ShaderVariant shader_variant = CanvasShaderGLES3::MODE_QUAD;
		const Item::Command *command = nullptr;
		Item::Command::Type command_type = Item::Command::TYPE_ANIMATION_SLICE; 
		uint32_t primitive_points = 0;
		bool lights_disabled = false;
	};
	
	
	
	struct DataBuffer {
		Vector<GLuint> instance_buffers;
		GLuint light_ubo = 0;
		GLuint state_ubo = 0;
		uint64_t last_frame_used = -3;
		GLsync fence = GLsync();
	};
	struct State {
		LocalVector<DataBuffer> canvas_instance_data_buffers;
		LocalVector<Batch> canvas_instance_batches;
		uint32_t current_data_buffer_index = 0;
		uint32_t current_instance_buffer_index = 0;