Angular app has to clear cache after new deployment

We have an Angular 6 application. It’s served on Nginx. And SSL is on. When we deploy new codes, most of new features work fine but not for some changes. For example, if the front-end developers update the service connection and deploy it, users have to open incognito window or clear cache to see the new feature. What type of changes are not updated automatically? Why are they different from others? What’s the common solution to avoid the issue?