Summarize Function

91asma2, I did tell you exactly why you get blanks. It's now up to you, I guess, what you want to do with this knowledge. If you still don't understand why you're getting blanks, then you have no choice but to revise/learn how context transition works in conjunction with CALCULATE in iterators like SUMX or FILTER. I guess there's no way around this, unfortunately.

You can start with this: How CALCULATE works in DAX - SQLBI

And please do not fall into the trap as many others do when they think that you can write correct DAX without learning the theory behind it. DAX can't be learned from examples. You have to learn the theory. Sorry.