You copy a harmless sentence after a private note, but the note still appears when you press Windows+V. Copying something new is not the same as clearing clipboard history. Windows 11 can retain several copied items when history is enabled.
Look for a pinned item
Open Windows+V and inspect the history. Microsoft's clipboard guidance says that clearing all items and restarting the PC leave pinned items in place. A restart is therefore not a reliable way to remove something you deliberately pinned earlier.
Use the item's menu to delete a specific entry. If necessary, unpin it first, then remove it and reopen the history to check. Before a screen-sharing session, do this with private content out of view. Do not paste a sensitive entry into a chat just to see what it contains.
Check the sync setting separately
Open Settings, then System and Clipboard. Cross-device history is a separate setting tied to a Microsoft or work account. Decide whether copied content needs to travel between your devices; local convenience alone is not a reason to enable sync.
For a simple rehearsal, copy a made-up phrase such as “meeting room sample”, find it in the history, and delete it. Reopen Windows+V to confirm what remains. Use invented text rather than a real password or customer note for this check.
Know what this removes
Deleting a clipboard entry does not remove the original note or a copy already pasted into a document. If content reached the wrong destination, inspect that destination separately. Clipboard cleanup addresses the clipboard; it is not a record of everywhere the text has travelled.