Insert button not working

All of a sudden, I can no longer insert a shortcode. I use Classic Editor and I get the same behavior in both Visual and Text mode. I click on the “Insert Shortcode” button and I get the popup with selection. I can move the mouse and they “hover” but when I click nothing happens. I don’t get the window to add information.

If I manually paste the shortcode, it works; it’s the visual UI that seems broken.

Thank you,

Iulian