Hey @JAalbers, thank you for posting in our Community.
It appears there may be compatibility issues between the new HubSpot form editor and your current GTM setup for tracking form submissions. Make sure your event listener setup (window.addEventListener) is correctly capturing the hsFormCallback event with onFormSubmitted. Check HubSpot’s latest documentation for any updates on tracking form submits with the new editor.
If this does not help, the more information, screenshots, and details you can provide, the better I can advise on the next steps.
Kindly,
Pam