CAA is a type of DNS record that allows site owners to specify which Certificate Authorities (CAs) are allowed to issue certificates containing their domain names. Some third party DNS providers do not have CAA records properly configured and as a result the Let's Encrypt validation/lookup will fail and your SSL certificate will not be installed.

You can read more about Let's Encrypt and CAA here: https://letsencrypt.org/docs/caa/

Unfortunately this is not an issue we can fix for you since you're using third party DNS services. You will need to speak with your DNS providers support team to setup proper CAA records on your domain so the Let's Encrypt installation can complete.