Andy Brownsword works around an issue:
I recently had an issue when sourcing data in Power BI from a server which was accessed by a DNS alias. Here I’ll demonstrate the issue and how to resolve it.
After entering the server details, we could be greeted with the message below:
The server name provided does not match the server name on the SQL Server SSL Certificate. Please contact your administrator or try changing your Connection encryption settings
Click through for a solution if you cannot re-issue the certificate with the relevant DNS alias.