Laravel 5 Route Model Binding not working on server

i have an issue with Laravel 5 Route Model Binding I am using the following Controller Method

public function destroy(PrimaryLocation $primaryLocation) {
    dd($primaryLocation->id);
    $primaryLocation->delete();
    return redirect()->back()->with('locationDeleted', true);
}

Where PrimaryLocation is an Eloquent Model

My RouteServiceProvider's boot function:

public function boot(Router $router)
{
    parent::boot($router);

    $router->model('user', 'App\User');
    $router->model('PrimaryLocation', 'App\PrimaryLocation');
}

And in my routes.php

Route::delete('deletePrimaryLocation/{PrimaryLocation}',
              ['as' => 'admin.deletePrimaryLocation', 'uses' => 'LocationsController@destroy']);

This setup works fine on my local Computer, but when i deploy the files to my development server, somwhere the model binding breaks; The Location won't get deleted on executing the method.

I did some var_dumps

dd($primaryLocation->id); 

on local computer this returns the correct id, but on the server it will just return null;

However if I do a

dd($primaryLocation)

The result is locally

    PrimaryLocation {#178 ▼
    #fillable: array:1 [▶]
    #connection: null
    #table: null
    #primaryKey: "id"
    #perPage: 15
    +incrementing: true
    +timestamps: true
    #attributes: array:4 [▶]
    #original: array:4 [▶]
    #relations: []
    #hidden: []
    #visible: []
    #appends: []
    #guarded: array:1 [▶]
    #dates: []
    #casts: []
    #touches: []
    #observables: []
    #with: []
    #morphClass: null
    +exists: true
  }

On on my Server nearly the same... but the attributes are missing:

        PrimaryLocation {#195 ▼
  #fillable: array:1 [▶]
  #connection: null
  #table: null
  #primaryKey: "id"
  #perPage: 15
  +incrementing: true
  +timestamps: true
  #attributes: []
  #original: []
  #relations: []
  #hidden: []
  #visible: []
  #appends: []
  #guarded: array:1 [▶]
  #dates: []
  #casts: []
  #touches: []
  #observables: []
  #with: []
  #morphClass: null
  +exists: false
}

Does anyone have a clue what might be going wrong?

[UPDATE]

if I comment out

// $router->model('PrimaryLocation', 'App\PrimaryLocation');

In me ServiceProvider, the local behaviour is the same as on the server. Maybe there's something wrong with loading the ServiceProvider? Maybe there is some sort of cache?