Change image on separate HUD blueprint

I am trying to change the frame around the active player portrait from within a blueprint that doesn’t contain the
widget element. I do this by making a reference to the GameHUD widget and accessing the publicly exposed widget
element Player_1_PortraitFrame, then setting the brush from texture. However, the portrait frame image does not
change as expected. Am I accessing the variable improperly or have I not created a proper reference or what?

Here is a screenshot of the BP which shows how I have the separate blueprints and made a reference within one.