Streamlit crashes/reset; connection to server lost

Both on my local machine, and when my script is deployed on streamlit via my github, when the very last checkbox is selected, it crashes. On the deployed app, the app refreshes. On my local machine, my terminal closes out of streamlit.

I’m not sure what’s going on. The only thing the check box does is display a selectbox that access keys within a dictionary.

Any thoughts/insights would be appreciated! Thanks!

Here’s my github link

My deployed app: