check in your module's nbm file what cluster is defined in Info/Info.xml.
- If it has wrong or missing value, you have to look in the module's pom configuration why it's so. Either it badly defined in the pom.xml or in the deprecated src/main/nbm/module.xml
- The module might end up in "ide" cluster because you defined defaultCluster parameter in your application
that's the behaviour for modules in the current nbm-maven-plugin. For osgi bundles the behaviour is more fluid as the bundle jars don't contain cluster information in the binary.