Ignore built-in trackpad always ignores
I have a new Magic Trackpad 2, which I bought to reduce palm interference when I'm typing on my laptop. I have big hands, and it keeps moving the mouse and tapping.
I went into Accessibility: Mouse & Trackpad, and checked Ignore built-in trackpad when mouse or wireless trackpad is present. Works great! No palm interference.
The problem comes when the wireless trackpad isn't there or turned off. It still ignores the built-in trackpad.
There are no other mice or trackpads that are currently connected, and I have to use Mouse Keys to maneuver to the Accessibility Preference Pane to turn the trackpad back on.
Anybody else see this?
MacBook Pro (Retina, 15-inch, Late 2013), macOS Sierra (10.12.4)