Often the Page number is used as the last value for the name generation. This is especially useful for packages. For single drawings the page number is not filled in. The result now for this now is 00001-.dwg ([docno]-[sheetno]. So don't show the separator when it appears on the last position of the generated number.
This problem can be solved by using a default value for the page number in the Cloud Configuration. Default values are available since Meridian Cloud 2023.1