QGIS » QGIS Application

Creating a virtual field for a layer and adding up 2 integer fields from that layer works fine. I get the correct results and I can use the virtual field for styling.

However, when doing a Joins with 2 layers and using a virtual field to add up an integer column from each layer, the results displayed are correct. But QGIS does not recognise the values when styling.

When I try to classify this in the Categorized styling option, for example, no data values are recognised.

Strangely, I am able to export the layer, including the virtual field, as a .csv which outputs all the correct results for the virtual field.

Attached are 2 simple point layers: Layer_A is JOINED with Layer_B, the virtual field is created in Layer_A. The virtual field calculates the Grade of both layers by simple addition.