Relationships and Reference Measure vs Direct Formula

[PBIDevNoob]

Hi! 

I'm trying to understand why my relationships doesn't seem to be working correctly and the difference between calling a measure from another measure and directly applying the formula in a measure. 

I have 2 tables with a one-to-many relationship. The first table just describes the ID, the second table has columns for ID, Year, Category, and Value. 

I added 3 measures for average. 

1. Average = AVERAGE('VALUE'[Value])
2. Average by ID Direct = AVERAGEX( VALUES('VALUE'[ID]), AVERAGE('VALUE'[Value]))
3. Average by Measure = AVERAGEX( VALUES('VALUE'[ID]), [Average]))

I then created a table/matrix with 'Values'[ID], 'Description'[Description], 'Values'[Category], with measures 2 and 3, and slicers for Category and Year.

For some reason, when I select from the Year and Category slicers, the measure "Average by Measure" I get a table where the description returns 2 rows for 1 ID:

Result

So I have questions regarding this.

1. Why did Measure 2 and 3 return different values when in essence they should be the same?
2. Why doesn't the relationship work even though I've set the direction to filter both. 

Note:

I realize that I can fix this by adding the relatedtable to measure 3, but I want to understand why. I also know that I can just use the ID from the Description table, but again, I want to understand why.

I've attached my sample in Google Drive: GDrive PBIX File 

Values TableDescription Table

Relationship

[Greg_Deckler]

Try using DISTINCT instead of VALUES. VALUES and VALUE aren't the greatest functions in the world and tend to be overused. They tend to mask data modeling issues.

[PBIDevNoob]

Thanks, but it pretty much returns the same thing. I'm also more concerned with knowing why the relationship isn't working correctly and why the using a measure in a measure returns a different value than using the same formula directly. 

[v-chuncz-msft · Accepted solution]

@PBIDevNoob 

Every measure has an implicit CALCULATE that you can’t see, so measures always trigger context transition from within a row context. Besides, you may try performance analyzer in Power BI Desktop to check query.

[amitchandak]

I think the problem , because of blank values. Please find the attached file.

[PBIDevNoob]

Can you tell me why? Also, if I create "Measure = 1" it returns something like a cartesian join for the IDs between the tables. Why does this happen even though I have a bi-directional filter on the tables. This doesn't make sense to me, and it feels like I'm not understanding a basic concept of relationships and measures.