the streamlit server is more speed than Heroku but there a minor issue on displaying
the running icon on streamlit server (running image on the upper right side doesn’t appear well)
and the x icon doesn’t appear well on the streamlit server while appear well on Heroku
Streamlit
!Heroku
I think the icons are possibly due to an issue in Streamlit v0.63. We’ll look into it and publish a fix if that’s indeed the cause
Working on it
Good news: we have just released a new Streamlit version that fixes this! 
We still need to upgrade the default Streamlit we use in our servers, but for now you can see the latest Streamlit by specifying the version in your requirements.txt:
streamlit>=0.63.1