The keymap defaultTabBinding doesn't work

I keep trying to get tabs to focus on the CodeMirror 6 Editor but it keeps shifting to other focusable elements, even after following the instructions CodeMirror Tab Handling Example. Here is a link to a demo displaying what I mean: https://codepen.io/okikio/pen/NWjzyRG?editors=0010

Interesting. I can see the issue in the codepen, but I can’t reproduce it locally with the same code. Keymaps in general don’t seem to work on that codepen (but do work for everybody else). If I simplify the code in the codepen to this, it works again:

import { keymap , EditorView } from "https://cdn.skypack.dev/@codemirror/view";
import { EditorState } from "https://cdn.skypack.dev/@codemirror/state";
import { defaultTabBinding, defaultKeymap } from "https://cdn.skypack.dev/@codemirror/commands";
let editor = new EditorView({
    state: EditorState.create({
        doc: "abc",
        extensions: [
            keymap.of([...defaultKeymap, defaultTabBinding]),

        ]
    }),
    parent: document.querySelector("#editor")
});

I think skypack is messing something up by duplicating dependencies, and that’s where the problem originates.

I also am having the same issue as okikio.
I am using codemirror inside of an ag-grid cell and when I setup the tab handling according to the CodeMirror Tab Handling Example it still focuses on the next cell rather than indenting. I would like to map Tab to acceptCompletion but so far I can’t get indentWithTab working.
I pulled out all of my editor setup except for what you listed in your answer and the behavior of the keyboard Tab still exits the codemirror editor and tabs to the next cell.