We have not been notified about such issue. Make sure you have the integration addon with Elelemntor https://wordpress.org/plugins/mphb-elementor/ installed and activated. In case it does not help, please, submit a ticket here, in order to have a closer look a the issue personally.
We have just released the Stratum plugin update, try updating the plugin to the latest version and check Elementor once again, it should work fine now.