### 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

_
GLES3::MeshStorage *mesh_storage = GLES3::MeshStorage::get_singleton();
			GLES3::ParticlesStorage *particles_storage = GLES3::ParticlesStorage::get_singleton();
			RID mesh;
			RID mesh_instance;
			uint32_t instance_count = 1;
			GLuint instance_buffer = 0;
			uint32_t instance_stride = 0;
			uint32_t instance_color_offset = 0;
			bool instance_uses_color = false;
			bool instance_uses_custom_data = false;
			bool use_instancing = false;
			if (state.canvas_instance_batches[p_index].command_type == Item::Command::TYPE_MESH) {
				const Item::CommandMesh *m = static_cast<const Item::CommandMesh *>(state.canvas_instance_batches[p_index].command);
				mesh = m->mesh;
				mesh_instance = m->mesh_instance;
			} else if (state.canvas_instance_batches[p_index].command_type == Item::Command::TYPE_MULTIMESH) {
				const Item::CommandMultiMesh *mm = static_cast<const Item::CommandMultiMesh *>(state.canvas_instance_batches[p_index].command);
				RID multimesh = mm->multimesh;
				mesh = mesh_storage->multimesh_get_mesh(multimesh);
				if (mesh_storage->multimesh_get_transform_format(multimesh) != RS::MULTIMESH_TRANSFORM_2D) {
					break;
				}
				instance_count = mesh_storage->multimesh_get_instances_to_draw(multimesh);
				if (instance_count == 0) {
					break;
				}
				instance_buffer = mesh_storage->multimesh_get_gl_buffer(multimesh);
				instance_stride = mesh_storage->multimesh_get_stride(multimesh);
				instance_color_offset = mesh_storage->multimesh_get_color_offset(multimesh);
				instance_uses_color = mesh_storage->multimesh_uses_colors(multimesh);