Turn on mask option on an adjustment layer

I'm glad you got it sorted, but I'd be interested if you were referring to double clicking the mask icon in the Properties panel, or double clicking a layer mask in the layers panel?  There's a Preference setting that controls double clicking a layer mask, but I am noit aware of any way to change what happens to the mask icon in the Properties panel.  We love learning new behaviours though, but I suspect you are right and that Photoshop got its knickers in a twist.