Hey James,
Nothing has changed and your webforms should be still working with no issues.
I tested a few here on my account and I have Leads being transferred over.
Has anything changed on your host that can be causing issues?
This one maybe easier to troubleshoot over a screen share with one of our Support members - please give us a call on the Method support line at 1.888.925.6238 x 2 and we'll be happy to take a look with you.
- Mortaza