Compare different versions not working for container page type

Description

Steps to reproduce

1. Create the latest version of the Alloy demo website.
2. Start the website and open CMS edit mode.
3. In the page tree, publish multiple versions of the “How to buy” container page type.
4. Click on “Compare different versions” for the “How to buy” container page
5. Select different versions from the “compare with” dropdown.

Expected: The view comparison of properties is based on the selected version in “compare with” drop-down.
Actual: No matter what version we select in the “compare with” dropdown, it always shows same comparison.