Custom Primitive Data changes done in the details panel on a placed BP Static Mesh resets to 0 after modifiying it

Custom Primitive Data values don't stick when editing them in the detail panel on a placed BP actor containing a Static Mesh Component.

Create a BP actor with a Static Mesh component with one Custom Primitive Data entry

Add the BP to the scene

Change the Custom Primitive Data (output the custom primitive data as color in a material to view)

See how the value is retained in the detail panel, but the read value in the material is reset to 0 after editing it.