Thanks Will, it worked as expected.
11:16:11.670 1/main/3a356/<> hit error com.couchbase.transactions.error.internal.AttemptWrappedExceptionNoRetry: com.couchbase.client.core.error.DocumentExistsException: Document with the given id already exists {“documentId”:“osn3”}
11:16:11.670 1/main/3a356/5ec3c rolling back on error
11:16:11.671 1/main/3a356/5ec3c Adding cleanup request for _default/_txn:atr-636-#35 to run in 15000 msecs
11:16:11.674 1/main/3a356/5ec3c added attempt TransactionAttempt{id=5ec3c,state=PENDING,atrColl=com.couchbase.client.java.ReactiveCollection@3ecedf21/_txn:atr-636-#35} after error
11:16:11.674 1/main/3a356/5ec3c rollback AttemptContextReactive{id=5ec3c,state=ROLLED_BACK,isDone=true,atr=_default/_txn:atr-636-#35,staged=[INSERT osn4, INSERT osn5]} expiryOvertimeMode=false
11:16:11.678 1/main/3a356/5ec3c aborting AttemptContextReactive{id=5ec3c,state=ROLLED_BACK,isDone=true,atr=_default/_txn:atr-636-#35,staged=[INSERT osn4, INSERT osn5]}, expiryOvertimeMode=false
11:16:11.690 1/main/3a356/5ec3c got ATR payments-metadata-dev/_default/_txn:atr-636-#35 ATREntry{atr=payments-metadata-dev/_txn:atr-636-#35,attemptId=5ec3c0c0-c2ac-4194-a5a9-75ae0fbee621,state=PENDING,expires=Optional[15000]ms,[age=0ms,cas=1591640171626496000ns/1591640171626ms]<-Only Accurate If ATR Updated,inserted=Optional.empty,replaced=Optional.empty,removed=Optional.empty,start=Optional[1591640171626]ms}
11:16:11.690 1/main/3a356/5ec3c aborting ATR payments-metadata-dev/_default/_txn:atr-636-#35
11:16:11.700 1/main/3a356/5ec3c aborted ATR payments-metadata-dev/_default/_txn:atr-636-#35
11:16:11.702 1/main/3a356/5ec3c deleting inserted doc osn4
11:16:11.710 1/main/3a356/5ec3c deleted inserted doc osn4, mt Optional[mt{vbID=636, vbUUID=217152030880143, seqno=9, bucket=payments-metadata-dev}]
11:16:11.711 1/main/3a356/5ec3c deleting inserted doc osn5
11:16:11.726 1/main/3a356/5ec3c deleted inserted doc osn5, mt Optional[mt{vbID=379, vbUUID=90127317062542, seqno=5, bucket=payments-metadata-dev}]
11:16:11.726 1/main/3a356/5ec3c marking ATR payments-metadata-dev/_default/_txn:atr-636-#35 as rollback complete
11:16:11.750 1/main/3a356/5ec3c rollback - atr rolled back