Trying to figure out conditional formatting of a cell based on its value and the value of another cell

One column my data has a product type (e.g. 1A, 1B, etc.), and another column has an attribute (e.g. WD, HM, etc.)

All product types can have all attributes. I'm trying to format the product type cell background based on a given combination of product type and product attribute (e.g. 1A + WD would be yellow, 1A + HM would be blue, etc.).

I've tried using a formula to control the formatting (e.g. ($J19 = "1A" and $I19 = "HM")), and setting the fill color, but it does not appear to be working (cell fill is not changing). Not sure what I'm doing wrong here.