SalesInvoice Extension Localization

I have created an extension for DocSalesInvoiceReportDSP class and more specificaly for the addDataFieldsForRdpTableRecord() method but it seems that SalesInvoiceLocalizationTmp (under else if (_rdpTableName == tableStr(SalesInvoiceLocalizationTmp)) is never reached. It is not reached even inside the base DocSalesInvoiceReportDSP class. Apparently only SalesInvoiceTmp is never reached. Is there somewhere else I should be checking?
Should I extend DocSalesInvoiceReportLocalizationDSP instead? what is the difference between DocSalesInvoiceReportLocalizationDSP and checking if the line is from SalesInvoiceLocalizationTmp?
inside addDataFieldsForRdpTableRecord() in DocSalesInvoiceReportDSP ? like in the following code in the replicas?
else if (_rdpTableName == tableStr(SalesInvoiceLocalizationTmp))
this.addDataFieldsForLocalizationLine(_addingRecord, _rdpTableRecord);

SalesInvoiceLocalizationTmp records are applicable just for #isoEE, #isoLT, #isoHU, #isoLV, #isoCZ, #isoPL countries. Check SalesInvoiceDP.insertIntoSalesInvoiceTmp() for details.
Is your legal entity from one of these countries?

No it is not one of these countries, it is DEU. Thanks for the information.