Brush ALT setting changed from hardness to opacity?

Normally, when you use a brush tool and press alt, you can change the hardness of the brush by holding down right mouse button and moving the mouse.

Now suddenly it changes opacity.

Is there a way to change it back to hardness?

I have "vary round brush hardness based on HUD vertical movement" selected, and I tried toggling it on and off and restarting photoshop. No help.