Virtual feed issue

I have a strange issue with a Virtual Feed.
I have make a new virtual feed (daily data) in this feed i have make Feed_a - Feed_b.
In the value i receive the wright value result. Buth in the graph i see a wrong value.

What i make wrong?
Here a lot of links about my config:

Can you attach those images to your post, please? I have increased your permissions now so you should be able to.

Hi Robert

I have shared the images in onedrive here the links:


No, the point about loading the images to this site is that when you or onedrive goes away, this thread is still meaningful. This is something that we ask everyone to do, so that your problem and its solution will always remain available.