Angular BehaviorSubject observable returns null

I pass data through components using behavior subject, but when I try to get it with subscribe, it shows null even if in service it returns real value.

Code reproduction:
https://stackblitz.com/edit/angular-ivy-dok6n6?file=src%2Fapp%2Fapp.component.ts

>Solution :

you have two instance of your service. one instance is created when inject your service and one instance is created when you use new AbstractComposeTemplateService() in AbstractComposeTemplate.
i fixed that. you can see that here