[Python] Session state is not respected when the options are not identical

In the example, Radio 1 and Radio 2 start with Option 2 as default value set via st.session_state.

When I change the valid options (via button callback),

Radio 2 retains the value while Radio 1 resets itself to the first value in the list of options.

Both the option sets will always have Option 2 as valid value.

I am trying to understnad why the difference in these bhaviors?

Issue is same with selectbox, pills etc. Just easily understandable with radio.

What am I missing.

Here is the code

import streamlit as st

options = {
'sel1': [
['Option 1', 'Option 2'],
['Option 1', 'Option 2', 'Option 3'],
['Option 1', 'Option 2', 'Option 3', 'Option 4']
],
'sel2': [
['Option 1', 'Option 2', 'Option 3', 'Option 4'],
['Option 1', 'Option 2', 'Option 3', 'Option 4'],
['Option 1', 'Option 2', 'Option 3', 'Option 4']
]
}

def showRadio(stCol, radioId):
with stCol:
st.metric(
f'Radio {radioId}',
st.radio(
label='With different options across runs',
options=options[f'sel{radioId}'][st.session_state.idx],
index=0,
key=f'radio{radioId}'
)
)


def updateDIdx():
'Update the session_state.idx upon button click in callback'

st.session_state.idx = (st.session_state.idx + 1) % 3


def showButton(stCol):
with stCol:
st.button('Change Options', on_click=updateDIdx)
st.metric('Options Index: ', st.session_state.idx)


def radio():
'''The main function'''

st.set_page_config(page_title="Radio Example")

# Set the session_state on first run
if 'idx' not in st.session_state:
st.session_state.idx = 0
if 'radio1' not in st.session_state:
st.session_state.radio1 = 'Option 2'
if 'radio2' not in st.session_state:
st.session_state.radio2 = 'Option 2'

cols = st.columns(3)
showRadio(cols.pop(0), 1)
showRadio(cols.pop(0), 2)
showButton(cols.pop(0))


if __name__ == '__main__':
radio()


Here is the sample output https://global.discourse-cdn.com/st.../0215eb2552601f41b502deb62c1273c900f9a5e4.gif

Streamlit version: 1.44.0 Python: 3.12

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