Unable to enable all plugins and toolbar features for CKEditor

Steps to reproduce:

1. Go to http://localhost:8080/xwiki/bin/admin/XWiki/XWikiPreferences?editor=globaladmin&section=WYSIWYG
2. Uncheck all plugins and features from the "DISABLED PLUGINS" and "DISABLED TOOLBAR FEATURES" lists -> image 1
3. Click Save
4. Go to http://localhost:8080/xwiki/bin/admin/XWiki/XWikiPreferences?editor=globaladmin&section=WYSIWYG -> image 2

Expected result: All plugins and features are disabled.

Actual result: The last plugin and feature are still selected.