Share intent from third-party apps fails on Android 16 / One UI 8 / Knox 3.12 (F-Droid & Play Store version)

[jo-bzh]

⚠️ Before posting ⚠️

• [x] This is a bug, not a question or an enhancement.
• [x] I've searched for similar issues and didn't find a duplicate.
• [x] I've written a clear and descriptive title for this issue, not just "Bug" or "Crash".
• [x] I agree to follow Nextcloud's Code of Conduct.

Steps to reproduce

1. Install latest Nextcloud app from F-Droid (after uninstalling Play Store version).
2. Grant all permissions: Access to all files (enabled via Settings > Privacy > Special app access), photos/videos, notifications, battery optimization disabled.
3. From any third-party app (e.g. Gallery, browser), tap Share > select Nextcloud.
4. Nothing happens: no upload dialog, no error message, share sheet closes silently.

Direct uploads via Nextcloud file picker work fine. Auto-upload also functional.

Expected behaviour

Share intent should open Nextcloud upload dialog, allowing selection of target folder and immediate upload.

Actual behaviour

Upload failure. No Internet connection.

Android version

16

Device brand and model

Samsung (One UI 8, Knox 3.12)

Stock or custom OS?

Stock

Nextcloud android app version

3.34.1

Nextcloud server version

32.0.1

Using a reverse proxy?

Yes

Android logs

No response

Server error logs

Additional information

Installation method

• F-Droid (latest version as of Nov 27, 2025)
• Previously tried Play Store version (same issue)

Additional context

• Scoped Storage fully permitted, SAF paths configured.
• Works perfectly on iOS device with same Nextcloud server.
• Manual file browsing/upload within Nextcloud app succeeds.
• Tried: cache clear, reinstall, path changes (/storage/emulated/0/), Knox tweaks.

This blocks core share-to-cloud workflow. F-Droid was recommended as Play Store workaround due to Google permission revocation, but issue persists on Android 16 + Samsung Knox stack. [web:49][web:61]

Related issues: #3301, #15109 (Android 16), #14895 (F-Droid signature)