Hi @Horak, Franz
The Version 2302 build 16130.21094 does not include Data Validation dropdown list autocomplete feature even the "Enable AutoComplete for cell values" is ticked under Editing options section.
I update Microsoft 365 Apps to Version 2308 (Build 16731.21064) which is released in January 2025, the feature is still available.
Based on my tests, I suggest you try Version 2402 (Build 17328.20550) on a test machine.
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