I don’t use emacs on macOS, so I can’t test that setup.
I didn’t configure the meta/alt keys with kkp, or with my terminal emulator.
Did you use this setting in kkp? Emacs and the terminal may be out of sync in how they are using alt and meta?
(setq kkp-alt-modifier 'alt) ;; use this if you want to map the Alt keyboard modifier to Alt in Emacs (and not to Meta)