make sure the device runs properly and then do the "download config" step to replicate the network information.
did that about 10 times, in between reboots, reloads, deleting and adding(detecting) Z Wave controller and fresh install. I suspected the ZTH200 controller to be at fault, so I used the mentioned tool to program the ZCU010 and that made the ZCU010 report correct to LMCE. I then programmed the ZTH as a slave controller.
So I think I have followed every trick in the book to get it up and running the "normal" way. Could it be that is has to do with the version of firmware on the ZTH200?