If you are receiving an error and not able to validate your DNS here is a quick item you can do to troubleshoot.
Depending on you DNS provider you may need to remove your domain from the host entry (unfortunately DNS providers treat these all different and not standardized)
Remove the .yourdomain.tld from the three separate records. e.g. In the example below my domain I am trying to verify is klowdcompanytest.com
I would remove the .klowdcompanytest.com from the three different DNS records.
Once you have made those changes in your DNS and allowed them to propagate try validating again. If it still fails, give support a chat here and we will continue to help troubleshoot.