To delete a device using Zentools or OZWCP you need to get them into the stick’s Failed List. You do that by repeatedly testing the node for fail. Be willing to try that 10 times. The “alive/good” status is cached and you must get past that. Then you can delete the failed node.
Note - it’s not clear if you did it that way or not... if yes, then my words may help someone reading this next month. 
