No response after form submit

Hello,
My contact form appears to be working fine. I am getting the submitted messages but there is never a response kicked back after selecting submit. Meaning a message such as “Your message was sent successfully. Thanks.” does not pop up. And when leave a required field blank, it doesn’t give me an error message. I am able to submit the form like this though I do not receive the email. Do you know why these auto responses are not happening. Any help with this is appreciated.

thank you,
Allison