Hi Alan,
Please try the steps below:
1. Select www.solnshki.com, click View DNS settings.
2. Check whether the domain purpose is SharePoint Online. If not, please change it.
3. Go to SharePoint admin center, select your public website and click Website Domains.
4. Change the URL to http://www.solnshki.com/.
5. Select your public website and click DNS Information. Copy the target address.
6. Go to your DNS name server, delete the A record and change the CNAME record point to the target address.
Thanks,
August Sun