Ctrl-N / P always move cursor by 2 lines while use `emacs/default` keyMap, But `vim` works well.

[Mitoax]

Whenever I use 'Ctrl-P/N', it always move 2 lines each time. Is there any directions or hints to soluve this problem?

Here is my init code

// codemirror 和 语言支持
import "codemirror";
import "codemirror/mode/markdown/markdown";
import "codemirror/addon/selection/active-line";
import "codemirror/keymap/emacs.js";
import "codemirror/keymap/vim.js";
import CodeMirror from "codemirror";

import "codemirror/lib/codemirror.css";
import "codemirror/theme/darcula.css";
import "codemirror/theme/ambiance.css";
import "codemirror/theme/solarized.css";
// import "codemirror/theme/solarized-dark.css";
import "./css/ambiance_patch.css";
import "./css/solarized_patch.css";
import "codemirror/theme/panda-syntax.css";
import "codemirror/theme/base16-dark.css";
import "./css/style.css";

......

    const editor = CodeMirror.fromTextArea(textArea.current, {
      lineNumbers: true,
      lineWrapping: true,
      matchBrackets: true,
      theme: options.currentEditorTheme,
      styleActiveLine: { nonEmpty: false },
      scrollbarStyle: "null",
      keyMap: "emacs",
      mode: "text/x-markdown",
    });
    editor.setSize("100%", "100%");

If change keyMap to vim, it works well.

Any one can Help?