We are using Export Report Data to Excel v2 (Export SQL and Report Data to EXCEL

That's the expected behavior. The plug-in exports the raw data. The raw data for a group is a group ID. The plug-in comes with the source code and can be enhanced by anyone to meet this requirement.

Since other people are already using this plug-in I wouldn't recommend updating the servlet one but creating a new one or adding a flag to say whether you want formatted names for objects (e.g. group names vs goupd ids) to avoid breaking any logic other people are using already to workaround the fact that the servlet returns the ID. This is just in case you decide to modify the servlet.

That's the expected behavior. The plug-in exports the raw data. The raw data for a group is a group ID. The plug-in comes with the source code and can be enhanced by anyone to meet this requirement.

Since other people are already using this plug-in I wouldn't recommend updating the servlet one but creating a new one or adding a flag to say whether you want formatted names for objects (e.g. group names vs goupd ids) to avoid breaking any logic other people are using already to workaround the fact that the servlet returns the ID. This is just in case you decide to modify the servlet.