Why can't I void an International Shipping Label?

[kb4dmf]

Why can't I void an International Shipping Label?  Ebay is not letting me do this for some reason.

[comics-scifi-collectibles]

@kb4dmf   You have only 5 days from the date of purchase to void the label.   You can not void eBay Standard Envelope labels>>    ( https://www.ebay.com/sellercenter/shipping/choosing-a-carrier-and-service/ebay-standard-envelope)

If neither of those limitations are an issue then what EXACTLY does it say when you try to void the label?