Thanks Jason explanation, that is most helpful.
It is strange after I read your advice I changed the WA validations, tested and all was OK.
I then decided to make a few changes to the form with html editor and discovered the form would not send the email.
I then found the "like" entry in WAvalidations had changed to an email field. This happened two or three times.
Image attached
btw what is the function of the hidden field?