AutoUpload reuploads the same files in a loop

[felix-walter]

⚠️ Before posting ⚠️

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

Steps to reproduce

Right now, I can only reproduce this with WhatsApp backups (all-binary files). I will describe this below. If the issue cannot be tracked down, I can try to reproduce it in a simpler way, possibly with ADB support.

1. Configure Uploads for /storage/emulated/0/Android/media/com.whatsapp/WhatsApp/Backups; configure to replace existing files on server.
2. Let it upload the existing backup.
3. Turn off Wifi, wait until WhatsApp updates its backup
4. Turn on Wifi
5. Upload starts and does not end until manual interventon or app is killed by system

Note: It does not happen all the time. Specifically, when other files are uploaded in-between, the process often stops. The uploads are always completed.

Expected behaviour

All updated files are uploaded only once and the upload process finishes afterwards.

Actual behaviour

The (binary) files are uploaded again and again.

Android version

16

Device brand and model

Pixel 8 Pro

Stock or custom OS?

Custom (explain in "additional information")

Nextcloud android app version

3.32.3 (logs below), 3.33.0 shows the same issue

Nextcloud server version

31.0.8

Using a reverse proxy?

Yes

Android logs

Snippet (privacy-related information removed): logcat-snippet.log

Server error logs

<IP> - felix [10/Sep/2025:06:16:44 +0000] "HEAD /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/wa.db.crypt14 HTTP/1.0" 200 821 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:44 +0000] "PUT /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/wa.db.crypt14 HTTP/1.0" 204 623 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:45 +0000] "PROPFIND /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/wa.db.crypt14 HTTP/1.0" 207 2199 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:45 +0000] "GET /index.php/core/preview?fileId=2084068&x=256&y=256&a=1&mode=cover&forceIcon=0 HTTP/1.0" 404 1112 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:45 +0000] "HEAD /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/chatsettingsbackup.db.crypt14 HTTP/1.0" 200 852 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:45 +0000] "PUT /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/chatsettingsbackup.db.crypt14 HTTP/1.0" 204 623 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:45 +0000] "PROPFIND /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/chatsettingsbackup.db.crypt14 HTTP/1.0" 207 2229 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:46 +0000] "GET /index.php/core/preview?fileId=2084064&x=256&y=256&a=1&mode=cover&forceIcon=0 HTTP/1.0" 404 1112 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:48 +0000] "HEAD /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/wa.db.crypt14 HTTP/1.0" 200 821 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:48 +0000] "PUT /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/wa.db.crypt14 HTTP/1.0" 204 623 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:49 +0000] "PROPFIND /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/wa.db.crypt14 HTTP/1.0" 207 2199 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:49 +0000] "GET /index.php/core/preview?fileId=2084068&x=256&y=256&a=1&mode=cover&forceIcon=0 HTTP/1.0" 404 1112 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:49 +0000] "HEAD /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/chatsettingsbackup.db.crypt14 HTTP/1.0" 200 852 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:49 +0000] "PUT /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/chatsettingsbackup.db.crypt14 HTTP/1.0" 204 623 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:49 +0000] "PROPFIND /remote.php/dav/files/felix/<serverpath>/com.whatsapp/WhatsApp/Backups/chatsettingsbackup.db.crypt14 HTTP/1.0" 207 2229 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"
<IP> - felix [10/Sep/2025:06:16:50 +0000] "GET /index.php/core/preview?fileId=2084064&x=256&y=256&a=1&mode=cover&forceIcon=0 HTTP/1.0" 404 1112 "-" "Mozilla/5.0 (Android) Nextcloud-android/3.32.3"

Additional information

It worked flawlessly until ~end of August (until the 3.32.3 update?).

The upload loop can be stopped manually by opening the "Uploads" view and quickly pausing+restarting uploads with the button on the top right. Nextcloud will then correctly consider the files as uploaded and not attempt to upload again.

I am using GrapheneOS and Nextcloud from FDroid, in case it matters. If anything is missing, I can try to generate additional logs or a screencast.

I am assuming this is not a duplicate of #15572 as I do not have bad connectivity. However, it may be caused by the same or a related underlying bug.