Looks like something might be interfering with the ajax calls....
Take a look at our FAQs at the bottom of our support page https://www.scripthat.com/support/ as the undefined buttons is listed there with some information on it, take a look at the other FAQ items as well there for WP Contacts. Make sure you're running the latest WordPress version (5.3.2), I believe yours is a little older. Also, make sure your browser cache is cleared for WP Contacts as well since you stated you just updated it, you might have some of the older code cached in your browser.
Let's start with that and let us know what you see.