[Bug] Impossible to download the file

Describe the bug

With some web sites downloading file does not work.

For instance with the CAF's site: https://www.caf.fr/, there is not error message but the expected PDF file is never downloaded.

There is the same issue trying to download the vaccination certificate from the state website: https://attestation-vaccin.ameli.fr/

How to Reproduce

1. Go to: https://www.caf.fr/ and connect yourself to your account
2. Select the link to download your last attestation (in french in the text: “Télécharger ma dernière attestation“)
3. Rapidly, 2 intermediate white pages are shown with only:
   a. first: the mention telling that loading is ongoing (in french in the text: “Chargement en cours… “)
   b. last: the link suggesting to click on the link if the document is not shown (in french in the text: ”Cliquer ici si le document ne s’affiche pas”)

Finally no document has been saved neither in the DDG's Downloads section, nor in the Android's file system.

Expected behavior

After both intermediate white pages have been shown, the PDF file should be available from the DDG's Downloads section.

By using another Web browser as Google Chrome, both intermediate Web pages are displayed too but then the PDF file is well saved and can be opened.

Environment

- DDG App Version: 5.144.0
- Device: Galaxy S10+ / Samsung SM-G975F/DS
- OS: Android 11

Begin by reproducing the download flow on the reported DuckDuckGo Android version, device, and OS using the CAF and vaccination-certificate sites, then compare the behavior with Chrome. Trace the app's download handling from the failing navigation and verify that the PDF appears in the DDG Downloads section and Android file system without regressing other downloads.