Cannot filter my transactions by the current user - Ember JS

So I am trying to filter my transactions by the selectedUser. I am not using sessions for the user system, instead I use a menu that updates selectedAt and I take the last selected user this way. Now I want to show the transactions only from the selected user. I've tried multple variants but they don't seem to work for me.

My controller looks like this

users: computed(function() {
    return this.get('store').peekAll('user');
  }),

  selectedUser: computed('users.length', function() {
    return this.get('users').sortBy('selectedAt').reverse().objectAt(0);
  }),

  transactions: computed(function() {
    return this.get('store').findAll('transaction');
  }),

My transaction model:

export default Model.extend({
  category: DS.attr(),
  name: DS.attr(),
  description: DS.attr(),
  amount: DS.attr(),
  date: DS.attr(),
  typeOfT: DS.attr(),
  user: DS.belongsTo('user')
});

and my User model:

export default Model.extend({
  fullName: DS.attr(),
  picture: DS.attr(),
  darkMode: DS.attr(),
  selectedAt: DS.attr('date'),

  transactions: DS.hasMany('transaction')
});

I can succesfully call each transaction for currentUser in the template by calling them like