Relationship issues showing BLANK values

Hi All,

I built a quick model with a lot of rows (10 million). The model analyses the YOY variances per product product group.

A product reference is linked to a product group. In some cases, the data might have mistakes and 1 reference is linked to multiple product groups.

For some reasons, I can see some "(blank)" values and I don't understand why. When I click on the revenue, it shows nothing as if it is empty.

Could you please help?

Thanks so much for your assistance!