This is going to be a bit hard to explain...

I am currently working on Excel Powerpoint. I have a few graphs on the powerpoint page that are linked to data on Excel. One of the graphs is a horizontal bar graph.

The data is coming from Spreadsheet A (let's call it). When I go to the graph, click on design, and then select data, a totally different spreadsheet, (call it Spreadsheet B), which is totally irrelevant to the graph, pops up. Spreadsheet A does not pop up at all.

The data from this graph used to come from Spreadsheet B, but no longer does. Yet it still automatically pops up.

I no longer want Spreadsheet B to pop up, only Spreadsheet A.

Any ideas on why this is happening and how to fix it??