Groupby toggle in Bar-Chart does work in Jupyter-Lab but not in .html

Here's my [conda environment](https://pastebin.ubuntu.com/p/Tc898NxFNn/).
I'm on Windows 10. Using Firefox 79.0 and Chrome 84.0.4147.135.

#### Description of expected behavior and the observed behavior

Using the following code, I'd expect the same behavior in both cases. However, while the first plot works flawlessly in Jupyterlab and the browser, the second plot does work in Jupyterlab but **not** in the browser.

#### Complete, minimal, self-contained example code that reproduces the issue

```
import numpy as np
import pandas as pd
import hvplot.pandas

df = pd.DataFrame({"value": [1, 2, 3, 5, 4, 3], "group": [1, 1, 1, 2, 2, 2] })

# This works in Jupyterlab + Browser
df.hvplot.bar(by="group").groupby("group").opts(width=400)

# This works in Jupyterlab, but the toggle doesn't work in the browser
df.hvplot.bar(groupby="group").opts(width=400)
```

There is no error output in the dev console.

Here what happens in the browser: