Bug with st.form

Using Streamlit
1

Hi I encountered a bug where the form submission is inconsistent

to reproduce it check the following:

import streamlit as st

@st.cache(allow_output_mutation=True)

def storedVars(session):

    return {'a':''}


var=storedVars(0)

newVar=''

with st.form("my_form"):

    newVar=st.text_input('',value=var['a'])

    if st.form_submit_button("Execute"):

        var.update({'a':newVar})

        st.write(newVar,var)

Try to enter a new value to the form and press ‘Execute’,
You can see that the new value you inputted is only submitted to the var ‘newVar’ once in every 2 times.

i.e.
fill in the form with 1, press Execute, you get result of 1 and 1
Then,
fill in the form with 2, press Execute, you still get result 1 and 1,
fill in the form with 2 again, press Execute, you now get result 2 and 2,