You can't enter deep sleep (a.k.a., hibernation) on command, IIRC.
I don't recall if the "Go to sleep/Suspend" entry is even visible in the Exit menu on Kindle, but even if it were, it would only trigger good old suspend, not deep sleep.
On the other hand, we can *delay* stuff properly so that the autosuspend plugin behaves as expected, which is good.
The other good news is: don't bother and don't worry about any that. Once in suspend, the device will enter deep sleep on its own after the required amount of time has been spent in suspend; no matter how suspend was actually entered.
TL;DR: What you're seeing is perfectly normal, and the keyword in your example is "quickly unlock"
. That doesn't leave enough time for the device to enter deep sleep, hence the lack of waking up banner.
FWIW, we log the exact hibernation timer on startup (if you have debug logging enabled), but AFAIK nothing ever actually changes it, and it's set at 1H (*after* suspend).