$page of type App\Model\Menu is incompatible with the type null|App\Classes\Interfaces\Linkable expected by parameter $object of App\Model\Link::connect().
(
Ignorable by Annotation
)
If this is a false-positive, you can also ignore this issue in your code via the ignore-type annotation
You can fix this by adding a namespace to your class:
When choosing a vendor namespace, try to pick something that is not too generic to avoid conflicts with other libraries.