Hi,
The last 3 or 4 firmware updates (official firmware) from the iOS app have resulted in the Dynamic Island notification persisting after the firmware update has finished - even across iPhone reboots.
The only way I’ve found to clear the status is to uninstall & re-install the app.
Prior to this it was working fine, with it being dismissed when it should be & I don’t remember making any settings changes which could affect it.
Might be related to iOS 18 since it’d have started being an issue around the time that came out.