Could possibly be a cross-domain issue if the lead is not identified.
Is this problem from already identified visitors (cookied leads) or ones that have filled out a form/clicked a link in an email to the exact page?
I believe the lead(s) are identified. I uploaded a list with filler fields but the filler field tokens are not populating on the landing page when I send the test. I wasn't sure if guided landing pages vs free form make a difference when pulling through the token.
Have you tried doing a batch sendout to yourself with these filler fields (not a sample) then it would give you the live version.
Send the email with the link to yourself with the batch and make sure you have included these filler fields so you can test clicking the actual email and then check the landing page.
This should not be an issue whether it's guided or free-form.
Another point, does the link from your email include the track link checkbox in the link settings?