### 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

_
glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE, GL_ZERO, GL_ONE);
					}
				} break;
				case GLES3::CanvasShaderData::BLEND_MODE_MUL: {
					glBlendEquation(GL_FUNC_ADD);
					if (state.transparent_render_target) {
						glBlendFuncSeparate(GL_DST_COLOR, GL_ZERO, GL_DST_ALPHA, GL_ZERO);
					} else {
						glBlendFuncSeparate(GL_DST_COLOR, GL_ZERO, GL_ZERO, GL_ONE);
					}
				} break;
				case GLES3::CanvasShaderData::BLEND_MODE_PMALPHA: {
					glBlendEquation(GL_FUNC_ADD);
					if (state.transparent_render_target) {
						glBlendFuncSeparate(GL_ONE, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
					} else {
						glBlendFuncSeparate(GL_ONE, GL_ONE_MINUS_SRC_ALPHA, GL_ZERO, GL_ONE);
					}
				} break;
			}
			last_blend_mode = blend_mode;
			last_blend_color = blend_color;
		}
		_render_batch(p_lights, i);
	}
	state.current_batch_index = 0;
	state.canvas_instance_batches.clear();
	state.last_item_index += index;
}
void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_render_target, const Transform2D &p_canvas_transform_inverse, Item *&current_clip, GLES3::CanvasShaderData::BlendMode p_blend_mode, Light *p_lights, uint32_t &r_index, bool &r_batch_broken, bool &r_sdf_used) {