Hi,
Indeed we do not cleanup properly the multi-value fields (multi choice, mutli lookup, multi person or group)  in the current version.
There is however an easy workaround that involves writing a small function within the report.

Select Report - Report Properties... in the Report Designer menu
Select the Code tab in the Report Properties dialog.
Copy the following function:

Public Function CleanUpMulti( ByVal s As String) As String
    Dim RegObj As New System.Text.RegularExpressions.RegEx(";#\d*(;#)?")
   
    Return RegObj.Replace(s, "; ")

End Function

Now, instead of retrieving directly the field value in the Report Layout View (eg : =Fields!Customers.Value), use the provided function (eg: =Code.CleanUpMulti(Fields!Customers.Value)).

The function uses a regular expression to replace the unwanted pattern by a semicolon and a space. You could obviously change the replacement string  as you like (eg: " - " or  vbLf, etc).

In the next version of ERSDE, we will be handling automatically the cleanup.
More interestingly, we will also be providing the possibility to duplicate items for specific multi-value fields so that it will be possible to group on such a field.
Let me know if that doesn't help.
Regards,