No page summarise features available 152.01

Just updated to 152 on Android (152.01 to be precise) and no page summarise features are available - not showing in the settings page, when using the menu (3 dots) on a web page and no shake to summarise either. No shake to summarise gesture under customisation or page summarise under ai controls either. My language is normally defaulted to system (English NZ) but changing to English UK or Enlgish US doesn’t fix this. It hasn't been highlighted as a release that's region locked: "Page summaries: Get key points from long articles with a tap or shake. Now available to all users in English." Any ideas? A bug?