I am trying to add a new website to the Brave publisher network but when I try to add, I get an error message: 

Uh oh! Your domain is NOT using HTTPS. You will need to fix that before continuing.

Anyone have a clue how to solve this? I have installed a certificate by Let's Encrypt. It's a Wordpress site and I am using a plugin to force https on the whole site and that seems to be working fine as well.

Funny thing is I have another identical site with the same configuration and that site I was able to add to the network without any issues. Any idea what I could do to get this working?