Browser reload does not always trigger a sync if new file is found created via external write

Steps to reproduce

1. Using a oC Google Drive mount and add a file via GD directly (not via oC)
2. Pressing force-reload on the browser accessing oC, the new file(s) appear
3. Sync does not get triggered
4. Renaming the file via browser accessing oC, the file gets renamed and synced.

Expected behaviour

Files should get synced when force-reload identifies new files on the backend.

Actual behaviour

At least one file needs a renaming, then all new files get synced

Note

When doing the same with eg. SMB, files added directly, force reload on the browser also triggers the sync process. Seems that the trigger process for sync is not homogen

Server configuration

Operating system: Ubuntu 18.04

Web server: nginx

Database: MariaDB

PHP version: 7.3

ownCloud version: (10.4)

Updated from an older ownCloud or fresh install: updated

Where did you install ownCloud from: tar

Signing status (ownCloud 9.0 and above):
all green

The content of config/config.php:

{
    "system": {
        "instanceid": "ocbdscdhwdo8",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "xxxx"
        ],
        "datadirectory": "xxxx\/data",
        "overwrite.cli.url": "https:\/\/xxxx",
        "dbtype": "mysql",
        "version": "10.4.0.4",
        "dbname": "xxxx",
        "dbhost": "localhost",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "logtimezone": "UTC",
        "installed": true,
        "filelocking.enabled": "true",
        "memcache.local": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "\/var\/run\/redis\/redis-server.sock",
            "port": 0,
            "timeout": 0,
            "dbindex": 0
        },
        "filesystem_check_changes": 1,
        "excluded_directories": [
            ".snapshot",
            "~snapshot"
        ],
        "upgrade.automatic-app-update": true,
        "quota_include_external_storage": false,
        "mail_smtpmode": "smtp",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpsecure": "tls",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_smtpauthtype": "LOGIN",
        "apps_paths": [
            {
                "path": "xxxx\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "xxxx\/apps-external",
                "url": "\/apps-external",
                "writable": true
            }
        ],
        "maintenance": false,
        "loglevel": 2,
        "theme": "",
        "show_server_hostname": false,
        "log_rotate_size": "20971520"
    }
}

List of activated apps:

Enabled:
  - activity: 2.5.3
  - comments: 0.3.0
  - configreport: 0.2.0
  - dav: 0.5.0
  - federatedfilesharing: 0.5.0
  - federation: 0.1.0
  - files: 1.5.2
  - files_clipboard: 1.0.2
  - files_external: 0.7.1
  - files_external_dropbox: 1.2.0
  - files_external_ftp: 0.2.1
  - files_mediaviewer: 1.0.2
  - files_pdfviewer: 0.11.1
  - files_sharing: 0.12.0
  - files_texteditor: 2.3.0
  - files_trashbin: 0.9.1
  - files_versions: 1.3.0
  - firstrunwizard: 1.2.0
  - market: 0.5.0
  - notifications: 0.5.0
  - provisioning_api: 0.5.0
  - systemtags: 0.3.0
  - updatenotification: 0.2.1
Disabled:
  - encryption
  - external
  - user_external

Are you using external storage, if yes which one: local/smb/ftp/gd/dp

Are you using encryption: no

Are you using an external user-backend, if yes which one: no

Client configuration

Browser: Opera

Operating system: W10x64

Logs

Web server error log

nothing relevant

ownCloud log (data/owncloud.log)

nothing relevant

Start by tracing the browser force-reload flow and its sync trigger for Google Drive external storage, then compare it with the SMB behavior described in the report. Done means files created externally appear and are synced after force-reload without requiring a rename; no specific files or tests are named in the issue.