Selection property created from UI has no selections

Description

Steps to reproduce:

1. In admin view, create a new page type.
2. Add a new property of the type 'Drop-down list'.
3. Edit the newly created property and add some selections under the tab 'Custom settings'.
4. Navigate to edit view and create a page of this page type.

Expected result:

The newly created property should have the selections you just added.

Actual result:

The property has no available selections.