[WP Smush Pro] WP Smush Pro CDN feature might need a domain validation

Hello everyone,
We love the clean, simple and efficient approach that was developed into WP Smush Pro for a CDN. It gives it a great plus-value.

We tried enabling it, and it broke the images of all our sites and disabled it back + emptied caches. We think we know why this happened and we'd like to know how to go about it.

This URL: https://697538.smushcdn.com/0/wp-content/uploads/sites/70/2018/06/9b8138_baabee88e1c84da9a97a7343931839f5_mv2.png?lossy=1&strip=1&webp=1
Was used to load the logo image of this website: https://www.erictruchonphoto.com/

When you browse to the first URL, it says that the site is not registered in the Hub.

Suggestion: Check if the site is registered to the Hub before changing the URLs to the CDN-generated ones. If the site is not registered, you can warn the WP admin through the dashboard (or any way you'd like).

Our main site is registered to the Hub, but not our many others. Do we have to add them manually one by one? Or is there any form of automation we can setup?

We create sites using the native way and change the URL to the final domain name https://www.domainname.tld

Thank you!