Error deploying app - connection refused while checking the health of the Streamlit app

I am having trouble deploying an app I successfully deployed back in Oct 2022.

Streamlit returns the following error after installing libraries during the build:

The service has encountered an error while checking the health of the Streamlit app: Get "http://localhost:8501/healthz": dial tcp 10.12.95.150:8501: connect: connection refused

I have pinned streamlit version and rebooted and re-deployed the app, still no luck.

Any suggestions

thanks @rohansaini886 but the only requirements in common with those deployments are

numpy
pandas
seaborn
streamlit
plotly

And they are commonly used in other streamlit apps.