I've been testing form handlers on a set of pages. Currently using Pardot to collect the submissions.
All forms will submit instantly if a user manually scrolls down to it, but when a scroll-to button is clicked (auto-scrolling to the form itself) it appends /#form to the address URL, and then submissions stop working...
This is the page in question:
It MAY have something to do with the Referral URL not matching up, as Pardot will recieve the info and then push back a success or error message.
Feel free to test this as it's not live yet, but please note in the comment box that you are testing.