When using vim keybindings Esc no longer works to change to normal mode.
From v3.2.2 (notice I'm pressing the Esc key and going into normal mode--cursor becomes a blinking block):
From v4.0.1 (pressing Esc but not going into normal mode--cursor remains blinking line):

When using vim keybindings
Escno longer works to change to normal mode.From v3.2.2 (notice I'm pressing the
Esckey and going into normal mode--cursor becomes a blinking block):From v4.0.1 (pressing
Escbut not going into normal mode--cursor remains blinking line):