Bridge Table Not Working

Thank you for sharing that.  I made some measures to just SUM the Value column from POS and Region tables so I could look at the amounts.

_POS_Value = SUM ( 'POS'[Values] )

_Region_Value = SUM ( 'Region'[Values] )

I also made a measure to look at the difference between your two test measures.

Test Measure Variance = [Region Test Measure] - [POS Test Measure] 

Looking at a breakdown of the number by brand under the correction category the Bridge[Brand] 'Liquid Paper 2-in-1 Bottle' only has a total amount in the 'POS'[Values] column of 81k where the Region'[Values] column has 498k so that looks like most of your variance.

Most of the other amounts are very close.

Could it be a problem with data missing from the POS table?