reCaptcha v2 not working

On my site eliserocher.divhunt.art the I’m using the Google ReCaptcha plugin.
I’ve defined a Form in my Contact page and added an attribute “dh-form 580” where 580 is the ID of my form.
The reCaptcha v2 box is displaying and I’ve got the checkbox correctly ticked.
However I’ve got the error message below.
Note: it is not the message I’ve setup in the form.