Checklist

• I have searched the existing issues for similar issues.
• I added a very descriptive title to this issue.
• I have provided sufficient information below to help reproduce this issue.

Summary

When updating to streamlit 1.53.0, a multiselect gets cleared immediately after selecting an item.
It works as expected when downgrading to 1.52.2 again.

Reproducible Code Example

import streamlit as st

class test_class:
    def __init__(self, text, value):
        self.text = text
        self.valu = value

elements = [
    test_class("A", 1),
    test_class("B", 2)
]
st.multiselect("Test", elements, format_func=lambda x: x.text)

Steps To Reproduce

1. select an item
2. it appears for a short moment then the multiselect is cleared / the element is deselected

Expected Behavior

The element should remain selected

Current Behavior

No response

Is this a regression?

• Yes, this used to work in a previous version.

Debug info

• Streamlit version: 1.53.0
• Python version: Python 3.14.0
• Operating System: Windows 11
• Browser: Edge

Additional Information

No response