Resolved
The update notice for Elementor 3.16 advises that it includes “substantial changes across the plugin” and recommends making a backup and testing on a staging environment.
The update breaks the Toolset integration which adds the View widget for inserting Views into Elementor pages and templates. The widget is not available to edit or insert when editing with Elementor, and they do not display on the front end.
Elementor issued version 3.16.2 which fixes this issue.