This is their third nuclear test and every single one has failed to cross the eight kiloton boundary at least. If this one is a plutonium weapon like the others

This is their third nuclear test and every single one has failed to cross the eight kiloton boundary at least. If this one is a plutonium weapon like the others it suggests that they are having major issues designing or fabricating the implosion lens around the nuclear material. It is quite striking that they keep conducting tests and reducing their usable nuclear stockpile further. It is almost like they don't have the capability to get a reliable warhead.