### Godot version

v4.0.beta14.official [28a24639c]

### System information

Windows 10, OpenGL

### Issue description

Vulkan and Mobile:
![Godot_v4 0-beta14_win64_kEcRNiMfNJ](https://user-images.githubusercontent.com/7782218/213967627-8e8755d9-2fe2-43b3-b197-f9f2840b7580.gif)

OpenGL:
![Godot_v4 0-beta14_win64_MQ233TZuPq](https://user-images.githubusercontent.com/7782218/213967651-ae463a6f-c867-4312-bdf1-525e1d7def01.gif)

At first I thought it was related to `set_buffer()`, but it turned out that `set_instance_*` also work incorrectly.
Probably the custom information is also set incorrectly, but I haven't checked it yet.

### Steps to reproduce

* Open MRP
* In the editor, select `MeshInstance3D` node and change the `Count` property
* -- or --
* Start the project and move the slider

You can also switch the renderer to Vulkan and compare.

### Minimal reproduction project

[set_buffer().zip](https://github.com/godotengine/godot/files/10476834/set_buffer.zip)

MultiMesh *multimesh = multimesh_owner.get_or_null(p_multimesh);
	ERR_FAIL_COND_V(!multimesh, 0);
	return multimesh->instances;
}
void MeshStorage::multimesh_set_mesh(RID p_multimesh, RID p_mesh) {
	MultiMesh *multimesh = multimesh_owner.get_or_null(p_multimesh);
	ERR_FAIL_COND(!multimesh);
	if (multimesh->mesh == p_mesh || p_mesh.is_null()) {
		return;
	}
	multimesh->mesh = p_mesh;
	if (multimesh->instances == 0) {
		return;
	}
	if (multimesh->data_cache.size()) {
		
		_multimesh_mark_all_dirty(multimesh, false, true);
	} else if (multimesh->instances) {
		
		if (multimesh->buffer_set) {
			Vector<uint8_t> buffer = Utilities::buffer_get_data(GL_ARRAY_BUFFER, multimesh->buffer, multimesh->instances * multimesh->stride_cache * sizeof(float));
			const uint8_t *r = buffer.ptr();
			const float *data = (const float *)r;
			_multimesh_re_create_aabb(multimesh, data, multimesh->instances);
		}
	}
	multimesh->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_MESH);
}
#define MULTIMESH_DIRTY_REGION_SIZE 512
void MeshStorage::_multimesh_make_local(MultiMesh *multimesh) const {