Downloading via share menu using SAF while no dowload folder was set before does not work

[iamrahatul]

Download from in-app works, but when I try to download from outside the app, with Vanced, by sharing, it doesn't work. It just creates an empty file, and it won't even show in the download manager.

Checklist

• I am using the latest version - 0.21.2
• I checked, but didn't find any duplicates (open OR closed) of this issue in the repo.
• I have read the contribution guidelines given at https://github.com/TeamNewPipe/NewPipe/blob/HEAD/.github/CONTRIBUTING.md.
• This issue contains only one bug. I will open one issue for every bug report I want to file.

Steps to reproduce the bug

1. Go to YouTube Vanced
2. Choose any video, click on share, choose NewPipe
3. Tap Download

Actual behaviour

Download screen pops up

Creates a file

But won't download, 0.00 kb

Expected behavior

I expected it to download the video, like it does when downloading from inside the app.

Device info

• Android version/Custom ROM version: Android 11
• Device model: Vivo Y220

[TobiGr]

Tested with latest dev: that problem is only present when SAF is used and no download folder was set before