Can I create a measure with components from two table fields?

I have two table fields - A & B.

In Field table A, I have total category of fruit (apple, banana, etc), monthly sales in $, month names.

In Field table B, I have total category of fruit again, monthly unit sales, month names.

Both table looks like this:

So I created a chart. X Axis is "Month", big filter is "Fruit", first Y is "Sales $" and second Y is "Unit". Some how the sales $ line looks normal with ups and downs but the unit line is flat with only one same number across all months. Something like below:

Anyone knows how to fix it? Somehow I think the relationship may do but still, I can't get it right.

Thanks!