Maybe one other thing to mention is that I was using SessionState.py (source) which does not work with streamlit version 1.5.0, see comment. So maybe it is somehow related to that?
Also there is another forum post I created which is also related to session state but also query parameters.
As I mentioned in this comment query parameters are also suddenly broken on streamlit cloud, so my assumption is there were some major changes on your side in last 1-2 weeks.
I don’t have many insights on how the deployment in streamlit cloud actually works but it is really obvious is that you are doing some things which are different then just running the app locally with streamlit run. The query parameter issue mentioned in my other post is an perfect example for this where the app works as expected locally but for some reason does not work in streamlit cloud and it is impossible to debug why…