PDF downloaded from Android browser is corrupted

Recently I discovered that PDF files generated by my WebApp were corrupted when downloaded from an Android browser.

So I created this simple WebApp to check and it seems that the issue continues.
https://kimsufi.jeremieleroy.com/cgi-bin/testdownload/testdownload.cgi

From iOS: no issue
From Windows: no issue
From MacOS: no issue
From Android: picture is OK, PDF is corrupted.

Would this be a Xojo bug or Android bug ?
Or is it only my phone ?

I tried the test app on my Nexus 6P with Chrome. I get an error : “Format de xxx non valide”. xxx is a number that is incremented with each download. I cannot download the picture.

Thank you for testing Louis.

Filename for both files should be “test.png” and “test.pdf”

So it seems that two Android phones have a different behavior as I am able to download the picture.

perhaps it is the webapp that failed. I am no longer able to download even the PDF file. I thought that perhaps something was wrong with my session, so I disconnected and waited some 15 minutes before I retried. I cannot download either file at this time.