Created a form in sharepoint associated with Excell but final form won't show all questions

I have create a form within sharepoint and that is associated with excell.  The form also has many branching options (and eventually I want to use Flow to send emails base don the response to those questions).  But when I go to the "preview" screen or the final version, the form will not go past the third question (there are 12 questions).  There must be a sticking point somewhere that I am missing.  Has any one run into this?