Thank You page and autoresponder e-mail

I have embedded the code for my form in a webpage and it works and I can complete and submit it. A message also arrive in my e-mail box of the submission. 

The problem is the Thank You page does not appear after submission (just get blank page).

I tried to fill-out your form to replicate the issue. However, it seems to be working on my end. After clicking the submit button, the Thank you page appeared:

I suggest to clear your browser's cache and retry.

Let me know if issue still persists, so we could check further.