Average of Average Pattern Inaccuracies

Hi all,
Getting a bit stumped on an average inaccuracy that I'm facing maybe someone can shed some light on a pattern that I may be missing.

Scenario: Creating an average completion calculating based on set criteria
Challenge:  Average seems to be correct at the criteria level, but at sub-total level seems incorrect.

 I have the following measures in the model:

CurrentRelease = 

// Select a release ID, if none is selected, return the max ID of an active release
VAR _ID = CALCULATE(MAX(Dim_Criteria[cID]), Dim_Criteria[Active] = "YES", ALL(Dim_Criteria))
VAR _Release = CALCULATE(MAX(Dim_Criteria[Release]), Dim_Criteria[cID] = _ID)

RETURN

_Release

t.Required = 

// Based on selected training release, return total number of required training executions.

VAR _Release = [CurrentRelease]
VAR _Required =  CALCULATE(SUM(Fct_Achieved[Required]), Dim_Criteria[Release] = _Release)

RETURN

_Required

t.Completed = 

// Based on selected training release, return total number of completed training executions.

VAR _Release = [CurrentRelease]
VAR _Completed =  CALCULATE(SUM(Fct_Achieved[Completed]), Dim_Criteria[Release] = _Release)

RETURN

_Completed

t.Average = DIVIDE([t.Completed], [t.Required])

Avg.Of.Avg = AVERAGEX(Dim_Criteria, [t.Average])

 

By using the average of the criteria [Avs.Of.Avg], I seem to be getting the correct value that I'm looking for:

 

However, the moment I add additional attributes such as user geography data, the numbers begin to look strange:

 

 

For example, coaching criteria, I am expecting 89.52% at sub-total level but the average of those seems incorrect. If I average out coaching (91.91 + 96.01 + 82.43 + 100 + 92.86 / 5 = 92.64%)

If I spin it a bit differently where I'm anazlying by Geography data, similarly, the total average is incorrect against the row context:

 

To be honest, I'm not sure which average number is correct, possibly none of it, however, the end-goal is to allow this data to be exported or used in a sub-model. When building a debug table, the average total says 92.54%:

Is there a DAX pattern that I'm not seeing or building correctly? Any guidance would be greatly appreciated. I've attached a sample pbix to the post.