Angular doesn't read system variables first time when page loads

wrote some code after following this (https://www.bennettnotes.com/post/angular-read-system-environment-variables/). I added API_URL in my system variable

Not sure if it will help if I create stackblitz. I tried to put as much as code below as I can.

It reads the system variable, but not at the very first page. (Note: In my local, it returns correct url even first time, I see this issue in DEV server)

Lets say I have a Home page(http://my-dev-url/home) and Configuration page (http://my-dev-url/config).

When I open chrome browser and enter Home page url, it (environment.API_URL) returns undefined. -> Now I click on Config hyper link, it picks the correct API_URL from system env. -> If I click on Home page link, it works with correct API_URL.

If I open chrome browser and enter config page url first time, it (environment.API_URL) returns undefined. -> Now I click on Home page hyper link, it picks the correct API_URL from system env. -> Now if I click on Config page link, it works with correct API_URL.

Code: (apart from what is already described in above url) environment.ts

export const environment = {
  production: false,
  dev: false,
  qa: false,
  local: true,
  API_URL: $ENV.API_URL
};

home.component.ts:

ngOnInit() {
        this.homeService
            .getTv(this.localIp)
            .subscribe((result) => {
                console.log(result);
            });
    }
}

home.service.ts:

import { environment } from '../../environments/environment';
            this.http.get(environment.API_URL + '/api/tv/' + this.localIp ).toPromise().then(response => {
                const data = response.json() as Tv;
                this.tv=data;

config.service.ts:

import { environment } from '../../environments/environment';

      this.http.get(environment.API_URL + '/api/' + 'config/1').toPromise().then(response => {
          const data = response.json();
      }).catch(error => {
          alert(error);
      });

Any clue what am I doing wrong.