Multiple active Relationships

I have three tables (Price Book, Quotes, Sales) with the following columns -- Part Number, Customer, and Rep.  I then created two additional tables -- Master Part Number and Master Customer with the following equations.

Master Part Number = DISTINCT(UNION(SELECTCOLUMNS('Price Book',"Part",[Part Number]),SELECTCOLUMNS(Quotes,"Part",[Part Number]),SELECTCOLUMNS(Sales,"Part",[Part Number])))

 

Master Customer = DISTINCT(UNION(SELECTCOLUMNS('Price Book',"Customer Name",[Customer]),SELECTCOLUMNS(Quotes,"Customer Name",[Customer]),SELECTCOLUMNS(Sales,"Customer Name",[Customer])))

 

When I  created the relationships between Master Part Number and the three other tables, everything works great.  I can create a page wide filter, and data is shown from all three tables correctly.

However, when I add the relationships between the Master Customer and the three other tables and try make it active, I get the following message

and my data looks like this:

 

Is there a way to have both relationships active?  I need the page to be able to sort by either customer or part number.