Thanks @BitBernd, that does it for me:
image1884×1459 216 KB
What’s interesting about this error is that it doesn’t require a re-run of app (for me), but rather, changing anything about the size of browser window makes the second chart’s div disappear. Makes me think there’s something confusing the React side of Streamlit.
Regardless of the why, I will pass your example on to our frontend team to see if they can figure out what might cause this.