Marketo's Native Known Visitor Custom HTML is not submiting.

[JayW]

I have the following page with a form that has the Known Visitor Custom HTML enabled.

https://go.forsta.com/KV-HTML-Test.html
I haven't added anything extra other than the standard four tokens it suggests.
The form loads as expected for known visitors.
However it doesn't allow me to submit. 
When trying to submit the button stays as it is. When attempting to submit I get the following error.

Any idea why? These KV HTMLs used to work well a while ago. Haven't tested it recently so I'm not sure when it became non-responsive.

[SanfordWhiteman · Accepted solution]

You’ll need to turn off reCAPTCHA for now to have KV HTML work. I’ll post a workaround soon.

[JayW]

Thanks @SanfordWhiteman !
I am yet to hear back from Marketo Support but they were hasty to push the blame on a different script that was pushing some hidden fields into marketo form on a different page.
Then I created this new test page and sent them that it is behaving the same way. 

Your explanation makes sense because I switched to the Marketo's native recaptcha option (from your good old method) only few weeks ago. And I'm sure the KV HTML used to work back then.

I guess I will adapt your Progressive profiling+KV Html lookalike solution to all forms. 

[SanfordWhiteman]

You have the right idea!