Adding a Filter changes values in a visual that should stay the same

[LucPoirier]

I'm a new Power BI User and I've got a lot to learn. 

Like many of the users posting here, I spent a lot of time with Excel, but Power BI is going to be much more effective for the amount of data I'm working with.

What I've tstarted using the platform for is tracking sales results and reporting it based on Store Number and Operator ID. I've been able to use "Filters on this Visual" for Product Number to trim Quantity (which is in a _Fact TransactionDetail table) value down to just the number of units sold by that user. I then created a Calculation to ignore that filter:

AllTrans = CALCULATE(COUNT('_Fact Transaction'[TransactionID]),ALL(Products))

This gives me enough information to math out a Conversion Rate:

ConversionRate = DIVIDE([AllTrans],SUM('_Fact TransactionDetail'[Quantity]))

All of this works splendidly, but when I try filter by a PromotionID (which is in a _Fact PromotionDiscount table), the number of Transactions changes dramatically and I can't figure out why.

_Fact Transaction links to both _Fact TransactionDetail and _Fact TransactionDiscount in a 1/* relationship, so I expected the filters to work the same.

I think what's happening is the Promotion Filter is changing how the visual understands the table, but I'm not getting the why.

Any help would be greatly appreciated!

[LucPoirier]

Adding info I didn't realize I'd missed above:

The reason I need to calculate by Promo is that we're tracking a few promotions that could consists of several different products and the Promo ID is the simplest way to track these sales.

[v-easonf-msft]

Hi, @LucPoirier 

Not sure, this can be related to the relationship between your current tables, the filter direction, table fields used in the visual ...

If convenient, please share your sample file for further research.

Best Regards,
Community Support Team _ Eason