Did you update the domain to match the domain associated with your VIP?
The browser will only return the cookie if the domain matches. This is likely why you are not seeing the cookie in the request, but you do see it on the client.
It's "decrypt". That was likely a typo in someone else's forum posting.
Yes, we are updating the documentation available on AskF5, however, they have had the challenge of keeping up with new commands that are not necessarily known or completely tested at the time the documentation is published.
This is one of the reasons we invested time in this forum, especially as a place to disseminate information that is unclear, incomplete and/or late-breaking.