I tested your form in my local server (but I remove recaptcha becasue on local it can't be used), and it worked.
Here is what you can do (for test):
1) go to menu item of form->click on Add form->run in iFrame->set to Yes.
After that go to your form->Advanced->More options->Settings->set width and height for form, also you can set to on Autoheight iFrame.
2) please try to test it with different templates.
Go to Extensions->Templates->Styles->and try to use any other template (just for test)
3) you can create a custom thank you page as an altenative, then last page is thank you page should be disabled.
In form->Advanced->More options->Submit pieces->End submit->you can put the code like this: