Monitoring Connector "Oracle Database" : service "Rman-Backup-Age" and "Rman-Backup-Problems" not working

Hi,
I’m using Monitoring Connector "Oracle Database”.
All services are OK, except both :

- Rman-Backup-Age :
Status is  “ CRITICAL: Rman 'DB FULL' backups never executed - Rman 'DB INCR' backups never executed - Rman 'ARCHIVELOG' backups never executed - Rman 'CONTROLFILE' backups never executed - Rman backups never executed.”

- Rman-Backup-Problems :
OK: During the last 3 days, number of backups completed: 0, failed: 0, completed with warnings: 0, completed with errors: 0

However rman backups works perfectly (daily): incr, full, archivelog 100% guaranteed.

Our rman catalog is on an external rman catalog database and channel type is SBT.

Why the connector didn’t seen our backups ?

Thank you
Nicolas