This started at least 4 releases back, I've just been waiting to see if it fixed.
https://screencast-o-matic.com/watch/cYQj05Hdfo
It used to be (and is normal grid behavior in other programs) that clicking "off" the selected line while editing would stop editing. Now it seems you have to hit enter. Any way to get the old behavior? You'll note that clicking on another row will *sometimes* stop the edit, but clicking into empty grid space won't.