So I am trying to create a very simple sales, cost chart with two lines.

 

I have one table for sales and it looks like this:

 

I have one table for costs that look like this:

 

 

Notice how the "Total costs" are calculated using a formula column.

 

 

Both tables are joined using lookup column for the column "Project".

 

 

 

When I try to add this into a chart I get two dots like this:

 

 

But it should be two lines on a timestamp.

 

How to fix?