Your observation is correct and as mentioned in the errata, the form scripts needed for dynamic elements are not initialized for the popups/modals like Elementor, where the form is not loaded on the page load. Such popups/modals load the form through AJAX on-fly, only once the popup/modal is opened.
I'm afraid, no single or simple function can be used to re-initialize these form scripts. Workarounds would be to either load the form in a new tab or use a different popup/modal, that loads the form without AJAX on the page load (and just show/hide it).