Custom dataset not returning data when linked to standard dataset in Financial Tax Register report?

We are in the process of customizing the Financial Tax Register report. A custom dataset has been added to the standard data model, but we are encountering an issue. When the custom dataset is linked to the standard dataset, it fails to return any data. However, when the custom dataset is not linked, it successfully retrieves data. Our requirement is to establish a connection between the custom dataset and the standard dataset while ensuring that the data is returned correctly