`C-[` in GUI mode does not work IN `lisp-mode`

[haze]

In any other major mode, C-[ defined by

(meow-define-keys
  'insert
  '("ESC" . meow-insert-exit)
  '("<escape>" . meow-insert-exit))

will escape insert mode and bring me back to normal mode.

In lisp-mode, this functionality does not work.

Am I missing something here that is special about lisp-mode?