I just installed Invisible Recaptcha 1.1, on a site with WP 4.9.1
I gave it protection to my login pages, and to a single Contact Form 7 form.
My CF7 form kept going to the orange border (fails to send due to “spam”).
And my WP login page stopped working… said my User/PW were wrong and wouldn’t let me in.
Other plugins I’m running:
Easy WP SMTP
I disabled the Invisible Recaptcha’s CF7 form protect, then that form would send again.
Then I disabled the Invisible Recaptcha’s login form protect, and then my user/pw was accepted.
I did have another Google Recaptcha Key (v2). I removed it completely, removed the key/secret from CF7’s settings, and re-enabled the Invisible Recaptcha plugin. It still would not work on the login or the contact form–the same results. I disabled it again and renabled the old v2 version of Recaptcha (with new key/secret) until this is fixed.