Hi zexpress and davo32683,
It’s generally not a quality control issue and is usually more of a time issue that is related to the way they compress their mattress and the type and density of the materials inside it.
Their roll pack machine compresses the mattress in several dimensions so it’s not unusual at all that it can take some extra time for it to reach its final dimensions (see posts #87 and #88 here) but if for some reason a mattress is a rare exception and doesn’t reach its final dimensions then if you call them they will be happy to help you and/or replace it (and of course they also have a 120 day trial period which offers a full refund if someone isn’t happy with their mattress for any reason).
Phoenix