Thanks! I reviewed the problem and the corresponding kb. Changed the glide.cmdb.query.execution_mode to v1 but no luck so far. The strange thing is that the kb (Calls to QueryBuilder for population of Service CIs and Global Search return no CMDB results when ex...) claims that Zurich Patch 6 fixes it and we already are on Patch 9. 
Not sure if a node restart would help as stated in the knowledge.