Hi, the workaround of using a static variable is ok but of course would not necessarily work well in any situation but I'm glad you got it working somehow :). However you're right, this is a known issue in NodeManager. https://github.com/mysensors/NodeManager/issues/176 should tell you why and answer your question #2. The solution unfortunately is not that easy since would require re-thinking the way sensors are mapped to child IDs. Work is in progress though (https://github.com/mysensors/NodeManager/issues/198)