Salesforce to MS Purview Integration

Hi, we are trying to setup Salesforce to MS Purview Integration for Data Mapping. Registration step is straightforward; however, we have run into issues trying to setup the scan itself. Error: Failed to testConnection: Exception when processing request: Connector Exception: Server returns ResponseCode:'400' We have raised this as an issue for MS Support but not making much progress. Any tips, advice or links to how to guides etc. would be very much appreciated!