Guests Not Working

I’m trying to use the Guests app but can’t seem to make it work. I have a clean install of Owncloud as below and have installed Guests from Market. In Admin -> Sharing I have emptied the Group Sharing blacklist and disabled the Guests whitelist. The video here provided by the documentation for Guests says that when it is enabled if you try to share a file, folder etc and type a username that doesn’t exist you will get the option to create a user as a guest. When I try to share an item all I see is a list of current users without the option to create a guest

Steps to reproduce

  1. Install Owncloud
  2. Install/Enable Guests from Market
  3. In the sharing dialog start typing a username that doesn’t exist

Expected behaviour

I should be given the option to create the unknown user as a guest

Actual behaviour

I receive a tooltip stating "No users or groups found for guestusername

Server configuration

openSUSE 15.1

Web server:
PHP version:
ownCloud version: (see ownCloud admin page)
Updated from an older ownCloud or fresh install:
Clean install
Where did you install ownCloud from: