ng-inline-svg | Angular directive for inserting an SVG file inline | Animation library

Most likely this is related with Firebase. Try to:

• Limit the use of valueChanges() using take(1) or some similar operation. For testing purposes, you could replace your entire call to firebase with a mock call that returns an observable or a promise that immediately completes. If it worked, it means your problem is in the call to the database.
• Use different versions of firebase and @angular/fire.

Angular Universal runs your code on the server. If your code generates any async operations or observables that never complete, your server will hang forever as it is waiting for the operation to complete.

valueChanges() is necessary on the client to have a "live" stream and reflect DB changes to the UI in realtime. On the server however, this behavior is the opposite of what you need, as you would probably want to fetch some data and render the page.

Your code should detect whether it's running on a browser or on the server and create the appropriate observable (one that completes after the first emission for server, one that stays open for browsers).

💡 NOTE valueChanges() is a common problem in this case, but the same concept applies to any other observable you might have subscribed to in your code.

📦 TIP You could use UniversalService from the @bespunky/angular-zen library. Just install the library and inject the service where you need it.

At some point, there was a version of @angular/fire which had a bug where the library had internally left an operation uncompleted, in turn causing a never completing NgZone task.

The solution was either upgrading or downgrading, but you had to find the matching firebase version.