Problem in translating ag-grid headers after reloading the page

Normally, when I use translation, it works fine. But when I refresh the page, the translations do not work properly.

ngOnInit() {
    this.addSelectCheckBox();
    this.columnDefs.forEach((col) => {
      col.headerName = this.translateService.instant(col.headerName || '');
    });
  }

default configs :

import { TranslateLoader, TranslateModule } from '@ngx-translate/core';
 

TranslateModule.forRoot({
          loader: {
              provide: TranslateLoader,
              useFactory: (createTranslateLoader),
              deps: [HttpClient]
          },
          defaultLanguage: 'fa'
      })

Correct mode:

Incorrect mode (after reload page):