JobScheduler Master running in an active cluster produces error messages "ORA-00001: unique constraint"

com.sos.hibernate.exceptions.SOSHibernateObjectOperationException: could not execute statement: 1 ORA-00001: unique constraint (SOS.REPORTING_INX_RTS_UNIQUE) violated
 [n/a]
	at com.sos.hibernate.classes.SOSHibernateSession.save(SOSHibernateSession.java:944)
	at com.sos.jitl.reporting.db.DBLayerReporting.insertTaskByOrderStep(DBLayerReporting.java:152)
	at com.sos.jitl.reporting.model.report.FactModel.synchronizeOrderHistory(FactModel.java:622)
	at com.sos.jitl.reporting.model.report.FactModel.synchronizeOrderHistory(FactModel.java:547)
	at com.sos.jitl.reporting.model.report.FactModel.synchronizeOrders(FactModel.java:363)
	at com.sos.jitl.reporting.model.report.FactModel.process(FactModel.java:102)
	at com.sos.jitl.reporting.plugin.FactEventHandler.executeFacts(FactEventHandler.java:256)
	at com.sos.jitl.reporting.plugin.FactEventHandler.execute(FactEventHandler.java:156)
	at com.sos.jitl.reporting.plugin.FactEventHandler.onNonEmptyEvent(FactEventHandler.java:97)
	at com.sos.jitl.classes.event.JobSchedulerPluginEventHandler.process(JobSchedulerPluginEventHandler.java:219)
	at com.sos.jitl.classes.event.JobSchedulerPluginEventHandler.start(JobSchedulerPluginEventHandler.java:120)
	at com.sos.jitl.classes.event.JobSchedulerPluginEventHandler.start(JobSchedulerPluginEventHandler.java:93)
	at com.sos.jitl.reporting.plugin.FactEventHandler.onActivate(FactEventHandler.java:67)
	at com.sos.jitl.classes.plugin.JobSchedulerEventPlugin$2.run(JobSchedulerEventPlugin.java:110)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.hibernate.exception.ConstraintViolationException: could not execute statement
	at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:59)
	at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
	at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
	at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)
	at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:207)
	at org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch.addToBatch(NonBatchingBatch.java:45)
	at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3001)
	at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3501)
	at org.hibernate.internal.StatelessSessionImpl.insert(StatelessSessionImpl.java:108)
	at org.hibernate.internal.StatelessSessionImpl.insert(StatelessSessionImpl.java:84)
	at com.sos.hibernate.classes.SOSHibernateSession.save(SOSHibernateSession.java:935)
	... 18 more
Caused by: java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (SOS.REPORTING_INX_RTS_UNIQUE) violated