Gravity Forms adds a new hidden field for the Honeypot and hash key in the webpage footer to validate that the submitted data is not spam. Explaining how the functionality works can be a bit complex.
The Anti-spam honeypot was not enabled. Why does my form still have a spam folder?
There was a recent submission that ended up in the spam folder again
Is there something else running behind the scenes that is not honeypot?
Then, it seems like it needs a closer look. Please open a support ticket here: https://www.gravityforms.com/open-support-ticket/technical/
, including the system report from the Forms → System Status page, and a link to the page where the form is located.