Make a wild guess about the json api links issue:

- notifyBelongsToChanged -> this._internalModel.notifyPropertyChange(key);
- notifyHasManyAdded -> this._internalModel.notifyPropertyChange(key);

i'll verify this with our app in the morning, which does use json api links

(and will rebase these comments away)

addon/-private/system/model/model.js

@@ -1040,7 +1040,7 @@ const Model = Ember.Object.extend(Ember.Evented, {
   },
 
   notifyBelongsToChanged(key) {
-    this.notifyPropertyChange(key);
+    this._internalModel.notifyPropertyChange(key);
   },
   /**
    Given a callback, iterates over each of the relationships in the model,
@@ -1112,7 +1112,7 @@ const Model = Ember.Object.extend(Ember.Evented, {
     //TODO(Igor): Consider whether we could do this only if the record state is unloaded
 
     //Goes away once hasMany is double promisified
-    this.notifyPropertyChange(key);
+    this._internalModel.notifyPropertyChange(key);
   },
 
   eachAttribute(callback, binding) {