Hi,
It is only a minor but annoying notice – from the log it seems like it might be triggered somewhere in an Elementor shortcode module. It says, that a certain variable is not defined. However I checked the plugin source on that location, and that variable is surely defined, so I am not sure what is triggering the issue.
First, clear the error log, then try going to the search settings and save them to refresh the database. Then if that does not work, try re-installing (deactivate, delete then install again) the plugin to make sure all the files are in the correct version.