Which error do you exactly get? Your www record is not proxied and comes with an invalid certificate, so if you try to access that from your iOS device for some reason you will naturally get a warning.
Is not an error, is a (i) icon before the site URL saying that the connection is not secure.
With other sites, example google.com appears the lock icon, but that icon doesn’t appear in mine using a mobile device.
I’ve found the problem. My website was loading an non-secure image (http://) in the footer on mobile devices, that’s why the locked icon wasn’t showing. After I fix this, the lock icon is showing without problems.
I didn’t found the reason why I can’t use the tool above, but I think everything is working properly.