We really need this to be addressed. Here's my original message for reference:
"We got this error message: Uncaught Error: Call to undefined method Elementor\Utils::is_ajax()
The reference to Utils::is_ajax is found in this file: /wp-content/plugins/cred-frontend-editor/vendor/toolset/toolset-common/inc/autoloaded/interop/handler/elementor/widgets/view/view.php
This function was deprecated as of Elementor 3.4.0. We replaced it with the WordPress default which is what Elementor recommended to do; please do the same with future updates."
We are actually preparing the update to our plugins to coincide with the wordpress 5.9 update. So we expect the update to arrive next week that fixes this issue permanently.