In the pane (if not visible, go to View > Report Data ), right-click Data Sources and select Add Data Source .

Even a mature product like VS 2019 Community has quirks. Here are solutions to the top three issues:

provide dedicated report designers that integrate directly into the VS 2019 IDE. Common Reporting Issues & Solutions

Do not overload VS 2019 with too many extensions. Each one adds to startup time and memory usage.