Void Status locks any voided Check or EFT to keep its reference and payee available.
Unlock Checks has been added to allow you to edit Voided checks, Printed, and EFT. However, best practice is to keep each Void and to not re-use its number or reference.
Clicking on the Lock icon for a payment that is Void will say, Locked by Void Status. This indicates this record is being kept and you may create a new payment to replace.