Sidebar expand icon disappeared after collapsed

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  1. Are you running your app locally or is it deployed? both
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    a. Is it deployed on Community Cloud or another hosting platform? Linux Server
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  5. Share the Streamlit and Python versions. Streamlit=1.5.0, Python=3.12

when sidebar expanded, everything looks ok:

but once I collapsed the sidebar, the expand button disappeared, and I can never expand again…

can any one help me?