Nextcloud File Locking gets out of sync

Sometimes the nextcloud android app break and fails to sync a note. Only opening the file in the browser and closing it again resolves it

Steps to reproduce

This issue is not 100% reproducible every time, but I found it using that way:

1. Use Android app to edit notes
2. Edit the file with the website again (after closing the android app)
3. Use the Android app again to edit again

Expected behaviour

The app syncs fine

Actual behaviour

The Server logs an error (attached below)

And the notes app shows an error that is not able to sync. Only if you go to the website, open and close the note, the sync works again

Server

• Notes app version: 6.0.1
• Nextcloud version: 34.0.1
• OS: Debian/LXC
• Web server: apache2 2.4.68-1~deb13u1
• PHP version: 8.4.23
• Database: mariadb

Nextcloud is ran behind an apache proxy server

Client

• Browser (incl. version): Firefox ESR 140.12.0
  • OS: Debian Trixie with Wayland

The other Client is Android 16 using the latest available version of the notes android app

Log files

{
  "reqId": "REDACTED",
  "level": 3,
  "time": "2026-07-17T04:12:11+00:00",
  "remoteAddr": "REDACTED",
  "user": "REDACTED",
  "app": "notes",
  "method": "PUT",
  "url": "/index.php/apps/notes/api/v1/notes/23228?",
  "scriptName": "/index.php",
  "message": "Controller failed with OCP\\Lock\\ManuallyLockedException",
  "userAgent": "Mozilla/5.0 (Android) Nextcloud-android/34.0.1",
  "version": "34.0.1.2",
  "exception": {
    "Exception": "OCP\\Lock\\ManuallyLockedException",
    "Message": "\"files/Notizen/Privat/Todo.md\" is locked, existing lock on file: files_lock/1ed743bc-1034-40ef-9711-3a5ab33e994c",
    "Code": 0,
    "Trace": [
      {
        "file": "/var/www/nextcloud/apps/files_lock/lib/Storage/LockWrapper.php",
        "line": 213,
        "function": "checkPermissions",
        "class": "OCA\\FilesLock\\Storage\\LockWrapper",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php",
        "line": 150,
        "function": "file_put_contents",
        "class": "OCA\\FilesLock\\Storage\\LockWrapper",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/Files/View.php",
        "line": 1235,
        "function": "file_put_contents",
        "class": "OC\\Files\\Storage\\Wrapper\\Wrapper",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/Files/View.php",
        "line": 680,
        "function": "basicOperation",
        "class": "OC\\Files\\View",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/Files/Node/File.php",
        "line": 56,
        "function": "file_put_contents",
        "class": "OC\\Files\\View",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/apps/notes/lib/Service/Note.php",
        "line": 174,
        "function": "putContent",
        "class": "OC\\Files\\Node\\File",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/apps/notes/lib/Controller/NotesApiController.php",
        "line": 174,
        "function": "setContent",
        "class": "OCA\\Notes\\Service\\Note",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/apps/notes/lib/Service/Util.php",
        "line": 25,
        "function": "{closure:OCA\\Notes\\Controller\\NotesApiController::update():164}",
        "class": "OCA\\Notes\\Controller\\NotesApiController",
        "type": "->",
        "args": [
          "*** sensitive parameters replaced ***"
        ]
      },
      {
        "file": "/var/www/nextcloud/apps/notes/lib/Controller/Helper.php",
        "line": 135,
        "function": "retryIfLocked",
        "class": "OCA\\Notes\\Service\\Util",
        "type": "::"
      },
      {
        "file": "/var/www/nextcloud/apps/notes/lib/Controller/NotesApiController.php",
        "line": 164,
        "function": "handleErrorResponse",
        "class": "OCA\\Notes\\Controller\\Helper",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php",
        "line": 165,
        "function": "update",
        "class": "OCA\\Notes\\Controller\\NotesApiController",
        "type": "->",
        "args": [
          "*** sensitive parameters replaced ***"
        ]
      },
      {
        "file": "/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php",
        "line": 78,
        "function": "executeController",
        "class": "OC\\AppFramework\\Http\\Dispatcher",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/AppFramework/App.php",
        "line": 137,
        "function": "dispatch",
        "class": "OC\\AppFramework\\Http\\Dispatcher",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/Route/Router.php",
        "line": 324,
        "function": "main",
        "class": "OC\\AppFramework\\App",
        "type": "::"
      },
      {
        "file": "/var/www/nextcloud/lib/base.php",
        "line": 1159,
        "function": "match",
        "class": "OC\\Route\\Router",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/index.php",
        "line": 25,
        "function": "handleRequest",
        "class": "OC",
        "type": "::"
      }
    ],
    "File": "/var/www/nextcloud/apps/files_lock/lib/Storage/LockWrapper.php",
    "Line": 82,
    "message": "Controller failed with OCP\\Lock\\ManuallyLockedException",
    "exception": "{\"class\":\"OCP\\Lock\\ManuallyLockedException\",\"message\":\"\\\"files/Notizen/Privat/Todo.md\\\" is locked, existing lock on file: files_lock/1ed743bc-1034-40ef-9711-3a5ab33e994c\",\"code\":0,\"file\":\"/var/www/nextcloud/apps/files_lock/lib/Storage/LockWrapper.php:82\",\"trace\":\"#0 /var/www/nextcloud/apps/files_lock/lib/Storage/LockWrapper.php(213): OCA\\FilesLock\\Storage\\LockWrapper->checkPermissions()\\n#1 /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php(150): OCA\\FilesLock\\Storage\\LockWrapper->file_put_contents()\\n#2 /var/www/nextcloud/lib/private/Files/View.php(1235): OC\\Files\\Storage\\Wrapper\\Wrapper->file_put_contents()\\n#3 /var/www/nextcloud/lib/private/Files/View.php(680): OC\\Files\\View->basicOperation()\\n#4 /var/www/nextcloud/lib/private/Files/Node/File.php(56): OC\\Files\\View->file_put_contents()\\n#5 /var/www/nextcloud/apps/notes/lib/Service/Note.php(174): OC\\Files\\Node\\File->putContent()\\n#6 /var/www/nextcloud/apps/notes/lib/Controller/NotesApiController.php(174): OCA\\Notes\\Service\\Note->setContent()\\n#7 /var/www/nextcloud/apps/notes/lib/Service/Util.php(25): OCA\\Notes\\Controller\\NotesApiController->{closure:OCA\\Notes\\Controller\\NotesApiController::update():164}()\\n#8 /var/www/nextcloud/apps/notes/lib/Controller/Helper.php(135): OCA\\Notes\\Service\\Util::retryIfLocked()\\n#9 /var/www/nextcloud/apps/notes/lib/Controller/NotesApiController.php(164): OCA\\Notes\\Controller\\Helper->handleErrorResponse()\\n#10 /var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php(165): OCA\\Notes\\Controller\\NotesApiController->update()\\n#11 /var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php(78): OC\\AppFramework\\Http\\Dispatcher->executeController()\\n#12 /var/www/nextcloud/lib/private/AppFramework/App.php(137): OC\\AppFramework\\Http\\Dispatcher->dispatch()\\n#13 /var/www/nextcloud/lib/private/Route/Router.php(324): OC\\AppFramework\\App::main()\\n#14 /var/www/nextcloud/lib/base.php(1159): OC\\Route\\Router->match()\\n#15 /var/www/nextcloud/index.php(25): OC::handleRequest()\\n#16 {main}\"}",
    "CustomMessage": "Controller failed with OCP\\Lock\\ManuallyLockedException"
  },
  "id": "REDACTED"
}

Start with apps/notes/lib/Service/Note.php around line 174 and apps/notes/lib/Controller/NotesApiController.php around lines 164-174, then trace the lock handling through apps/notes/lib/Service/Util.php and lib/Controller/Helper.php. Reproduce the Android/browser editing sequence and inspect the files_lock LockWrapper trace. Done means the note can sync after alternating clients without the file remaining blocked or producing ManuallyLockedException.