Folder size bug

It seems that when you open the owncloud client app the parent folder sizes in the root directory are stuck until the client is rebooted. The child folders seem to get their updates as they should, but not their parent directories. It shows a successful last sync too. I rebooted the PC and got the right sizes to show then. It happened both times I tested.

Steps to reproduce
1.Make a noticeable chance to the content size of a subfolder (child folder) that owncloud is syncing.
2.Observe the child folder shows an updated size, the parent folder does not.
3. Restart required.

Expected behaviour
Show current size

Actual behaviour
Shows old size

Client configuration
Client version: 2.2.4
Client operating system: Windows10

Server configuration
Operating system: Ubuntu16
Web server: Apache
Database:SQL
PHP version:Latest
ownCloud version (see ownCloud admin page):9.1.3
Updated from an older ownCloud or fresh install: fresh
Special configurations (external storage, external authentication, reverse proxy, server-side-encryption):
external hdd
ownCloud log (data/owncloud.log)

Please paste possible errors in the following code block, see https://central.owncloud.org/t/how-to-find-webserver-or-oc-logfile-enable-php-logfile/808 for more info

Please report this directly to the bugtracker on https://github.com/owncloud/client/issues