When loading dimensions from the backend in SQL, Member type properties have 2 fields in the Dimension table, one for the member label, and one for the internal member id. The following stored procedure can be called to update the member ids from the member labels on your member property fields.

Brp_UpdateDimensionPropertyMemberIds DimensionName, Prefix, PropertyName, SourceDimensionName

Example:

exec brp_UpdateDimensionPropertyMemberIds 'Property', 'O', 'Client', 'Client'