Classloading issues running flowable 6.4.0 on Karaf

Event though my issue is on Flowable-engine v5.23.0 (as v6.4.0 currently issue), I have some class loading issues in regard to classes/beans used within a task delegate that are imported from another module. (see details in my last post under Flowable-engine in OSGi - Tutorials/examples?).

Has anyone met that situation?