Pro Forms Webhook - Debug: Show Response in Console

When the Debug: Show Response in Console is turned on: the console logs an error. The form does not submit.

When this option is turned off, the form submits and the webhook fires.

Failed to load resource: the server responded with a status of 500 ()
bricksforge_elements.js?ver=1702493985:1 SyntaxError: Unexpected token ‘<’, "<!DOCTYPE "… is not valid JSON

bricksforge_elements.js?ver=1702493985:1 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading ‘success’) at bricksforge_elements.js?ver=1702493985:1:61530

Thank you,