I have no experience with Marketo Form but it looks like some kind of plugin / iframe solution.
So it might be that the experience is dependant on the specific browser you are using.
Perhaps you can try to check the same page in chrome, firefox, safari, etc. and also on desktop, mobile, tablet....

Hi Ethan,

Yes, we've noticed similar behavior before. In many cases, the difference comes down to how the Marketo form is configured or how the page handles the submission. If the form submits normally, the page may refresh and append the alid parameter to the URL. If JavaScript successfully intercepts the submission, the custom confirmation message is displayed instead.

A few things worth checking are:

• Whether the behavior is consistent across different browsers or devices.

• If there are any JavaScript errors on the page when the issue occurs.

• Whether the Marketo Forms API or any custom scripts are interfering with the submission flow.

• If browser extensions or caching could be affecting the form behavior.

If you can share the form URL or any custom implementation details, it would be easier to help identify the root cause.

Hi Ethan, the Marketo Form extension can behave differently depending on how the form is configured. Common reasons include different redirect settings, custom JavaScript, browser caching, cookies, or conflicts with other scripts on the page. If the Marketo Form extension is set to redirect after submission, you'll typically see the page refresh with parameters like the lead ID added to the URL. If it's configured to display an inline success message, the custom confirmation message will appear instead. I'd recommend checking the form settings, browser console for errors, and any custom scripts that might be affecting the Marketo Form extension behavior. TimerClock