media::copy doesn't seem to work as expected

[typoworx-de]

https://spatie.be/docs/laravel-medialibrary/v9/advanced-usage/moving-media#copying-media

$mediaItem = $model->getMedia()->first();
$copiedMediaItem = $mediaItem->copy($anotherModel);

In my case this error is raised after trying this code:

In ForwardsCalls.php line 50:
                                                                                     
Call to undefined method Illuminate\Database\Eloquent\Relations\MorphMany::sync() 

I'm using:
laravel/framework:^8.0 (installed: v8.55.0)
spatie/laravel-medialibrary:^9.0.0 (installed: 9.7.1)

[typoworx-de]

Okay... just got it working! My fault, for some other relations I already had own copy-process uning "model->getRelations()" which produced this unexpected error as Media-Relation doesn't support sync method there. I excluded 'media' there explicitly and now its working ;-)