Server name has already been used after you deleted it
after you delete Azure SQL server, you are trying to create the same server name in a different subscription you own
the server creation process failed with error 60080 - Server name has already been used
This happen because we keep the server name for couple of days in case the original subscription still needs the server name and remove it by accidentally.
in this time period only the original owning subscription can recreate the server name again.