Hi Rob,

It sounds like you're having trouble changing the data range for your Pivot Chart. Here are some steps you can try to resolve this issue:

1. Make sure that your Pivot Table is selected. You should see the Pivot Table Tools tab appear in the ribbon.
2. Click on the Analyze tab in the Pivot Table Tools tab.
3. In the Data group, click on the Change Data Source button. This will open the Change PivotTable Data Source dialog box.
4. In the dialog box, you should see the current data range for your Pivot Table. If you want to change the data range, click on the button next to the Table/Range text box.
5. This will allow you to select a new range of cells for your Pivot Table. Once you've selected the new range, click on the OK button to close the dialog box.
6. Your Pivot Table should now be updated with the new data range. If you go back to the Pivot Chart and click on the Select Data button, you should now be able to change the data range for your chart.