Interface help, please

First: Flute would play but last note would "stick"; that note would keep on playing even after it showed as nothing on the graph.

So I experimented and when I sent that instrument to "piano roll" I was able to get the "sticking" note to stop playing.

BUT now I see flute in this "graph" mode and can't get back to "keyboard editor" mode for that instrument.

Any ideas? I would also welcome any ideas as to how that last note "sticks" and can be "unstuck" without having to "send to piano roll".

Please see image:

Why not use the piano roll? I don't know if you...

once you move something to the piano roll you c...