此问题可能与浏览器缓存和Zone.js有关。您可以使用HttpClient模块下载文件，并在HttpHeaders选项中设置responseType。同时，将下载过程移出Zone.js的范围以避免在下载过程中出现应用程序错误。

以下是示例代码：

import { Component, NgZone } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';

@Component({
  ...
})
export class DownloadComponent {
  constructor(
    private http: HttpClient,
    private zone: NgZone
  ) {}

  downloadFile() {
    const url = 'http://example.com/largefile.pdf';

    const headers = new HttpHeaders()
      .set('Accept', 'application/pdf');

    this.http.get(url, {
      headers: headers,
      responseType: 'arraybuffer' // add responseType option
    }).subscribe(
      (response: ArrayBuffer) => {
        this.zone.runOutsideAngular(() => { // run outside of zone.js
          const blob = new Blob([response], { type: 'application/pdf' });

          const link = document.createElement('a');
          link.href = window.URL.createObjectURL(blob);
          link.download = 'myfile.pdf';

          link.click();
        });
      },
      error => {
        console.error(error);
      }
    );
  }
}