The author has a very literal notion of "shippable". Shippable could mean to a beta group. It could mean to the public. It could mean that the feature is "done" but not turned on or it's hidden behind a feature flag.
Also, you are supposed to have retrospectives after each sprint to improve. This sounds like a discussion that should have happened with the OP's team at a retrospective.
Also, you are supposed to have retrospectives after each sprint to improve. This sounds like a discussion that should have happened with the OP's team at a retrospective.