"Disable touchpad while typing" doesn't disable touchpad

I’m using ubuntu-mate 17.10.

Under the touchpad settings in the Contro Panel, the “disable touchpad while typing” setting doesn’t seem to do anything. My pointer is still jumping all over the screen and screwing up my typing.

I need to be able to disable the touchpad while I type. I’m also a slow typer and I need to be able to adjust the delay for when the touchpad is re-enabled.

I tried to find a setting dconf-editor but I couldn’t see anything.

There’s a ppa for that, but it really screwed with my x session. I purged it.

And yes, I’m having the same issue.