Cannot add existing page via Taxonomy pages grid field add existing component

[NightJar]

This is a reasonably fresh SilverStripe install, with "Home", "About us", and "Contact us".
However typing "Home" or "About" into the search box on the right in the above image returns no results.

Context

CWP recipe kitchen sink, 2.x-dev, currently using SilverStripe 4.3.x-dev.

• Logged in as Admin
• create Taxonomy Type "Type2"
• create Taxonomy Term "Parent2"
• create Children "Child2"
• attempt to assign that child to a page on its Pages tab relationship editor.

[robbieaverill]

To be fair, I don't know whether this GridField should even exist. It might be automatically scaffolded in CWP 2.x - worth regression testing against 1.x