ReSharper deletes used imports after code cleanup

I'm developing an Angular 4 app and I have the following imports:

    import { Injectable } from '@angular/core';

    import { Http } from '@angular/http';

    import { Observable } from 'rxjs/Observable';

    import { MyObject } from '../../models/shared/my-object';

After code cleanup only the last import is left, the others are removed. Is this a bug or should I reconfigure something in the settings? The only changes I've made in my settings are as per this post and I also enabled Angular in HTML but that is not important here.