'hamburger menu' inoperable - small screen header navigation

[phillxnet]

Thanks to Heather (in-person) for highlighting this issue. When viewing the docs on a small (narrow) screen, i.e. a mobile device, the 'hamburger menu' element is non-functional:

Reproducer

Desktop browser

Wider OK

We have the regular menu items available directly:

Narrower NON Functional

When the theme adapts to a narrower display, via the 'hamburger menu' container, menu-bar navigation is lost as this new element is non-functional.

The expected behaviour is as per our main website: here the 'hamburger menu' container, when clicked, produces a drop down of the prior (wider screen) nav-bar/top-panel menu items.

[phillxnet]

Considering for this issue a wholesale update of our dependencies: https://getbootstrap.com/docs/5.3/getting-started/introduction/https://getbootstrap.com/docs/5.3/getting-started/introduction/

• https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css
• https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js