"0x001B" = "cancel:"; was "0x001B" = "cancelOperation:"; is AppKit binds Escape to cancelOperation:, and that is the selector applications implement. LibreOffice has cancelOperation: in its selector table and does NOT have cancel:, so Escape arrived, was translated correctly, reached the application keyDown, turned into doCommandBySelector: cancel: and stopped there. Nothing was missing from the keyboard path; one name was wrong. NSResponder has the default cancelOperation: that AppKit documents now, which passes the older cancel: along the responder chain, so this framework own panels keep working: NSSavePanel, NSPopUpView and NSComboBoxView all implement cancel: and none of them implements cancelOperation:. Measured after: doCommandBySelector: cancelOperation: is followed by sendKeyInputAndReleaseToFrame code=1281 char=27, which is KEY_ESCAPE, and an open File menu closes (docs/wayland-escape-closes-menu.png). Typing straight after goes to the menu bar rather than the document, which is what LibreOffice does everywhere: one Escape leaves the menu, a second leaves the menu bar. What found it was tracing the application own doCommandBySelector: beside the key path. Return already worked through insertNewline:, so the two side by side said the machinery was right and one binding was not.