The gtm.formInteract event is not an officially supported event by Google Tag Manager (GTM). It appears to have been a test event briefly available in some GTM containers but has since been removed.
While third-party developers might create custom events like gtm.formInteract, it's crucial to understand that these events are not officially endorsed by Google. Consequently, they may lack reliability and consistency across different containers.
If your GTM implementation relies on a custom event like gtm.formInteract, it is advisable to transition to an officially supported event by Google, such as the built-in Form Submit event or the Click event. Doing so ensures the reliability of your tags and their continued functionality in the future.