Deleted files and folders reappear

There are several users syncing some folders. When any user deletes a file or folder, they re-appear after a while.

Steps to reproduce
1. delete a file/ folder
2. wait for a few minutes
3. deleted file/folder reappears

Expected behaviour
deleted file/folder shouldn't be there anymore

Actual behaviour
deleted file/folder reappears

Client configuration
Client version: 2.2.4
Client operating system: win10

Server configuration
Operating system: Centos 6
Web server: apache 2.2
Database:MySQL 5.1
PHP version: 5.4.16
ownCloud version (see ownCloud admin page):9.0.2
Updated from an older ownCloud or fresh install:updated from 8
ownCloud log (data/owncloud.log):

Special configurations (external storage, external authentication, reverse proxy, server-side-encryption):

Before posting please snip make sure that you're running the latest available version for your oC release: https://owncloud.org/changelog/