Not sure what is meant to happen, but if you plan some segments, and then hit enter, everything will be blank until you move the mouse, where the uncommitted plans will still be there.
do you press enter while drawing a stroke?
Okay, that is not supposed to work at all, so I will treat this as an UI issue
Implement expected materialize behavior #120
Feels better if you can immediately press enter even during a stroke, so I implemented it like that!