Undefine message when submitting the Newsletter form

[purplecodes]

User is getting an undefine message after entering email on the Newsletter form.
https://www.transamericanheroes.com/sizzify-failure/
screenshot: https://prnt.sc/m2qt8c

Ticket link: https://wordpress.org/support/topic/undefined-error-on-newsletter-form/#post-11049967

Steps taken:

• installed poopy.life
• installed Elementor and Sizzify Lite only
• created a page and edited it with Elementor
• added a section for the Newsletter Form widget
• entered API key and List ID from Mailchimp
• tested and got the error.
• changed the type from email to text, same issue -->> https://prnt.sc/m2qu0j

[purplecodes]

@contactashish13 kindly look into this when you can? Let me know if you need more information.

[mileamadalin]

+1 Can you fix this one? Our customers complain about this one

@contactashish13

[mileamadalin]

@radu-themeisle can we please make the release here?

[radu-themeisle]

Yes, but first we need to fix some more issues which I missed on the first test. Hopefully at the beginning of next week we'll have a release.
ref codeinwp/themeisle-content-forms#23