Shift-Click not working

This is a new test installation at home, not on the Internet, on a PC with newly installed Debian, PHP, WordPress & the free version of Hueman.

My PC has up-to-date Windows 11 and browsers. I’ve tried with Edge and with Chrome.

When I try ‘shift-click’ to edit the Primary widget zone nothing happens. This is in the in Main Body Design -> Column layout for the main content.

I have selected Two columns with Content Left is selected, the rest of the controls are unaltered – the global layout isn’t forced, everything inherits the global layout. I added a Facebook social media widget and Sidebar Top Boxes is checked. However it makes no difference if I uncheck it.

There are no problem using shift-click to select multiple items from (e.g.) Windows Explorer.

I’ve run the health check, installed a few more bits of PHP & restarted Apache. No change.

I normally use the left shift key, I’ve tried with the right. No better.

I’m very frustrated as Hueman is a very flexible theme and I’d like to stick with it. But maybe not…

The page I need help with: [log in to see the link]