Database Software

I have a daily cleanup script after each backup script to validate backups made. At some point the command "list failure;" started to give possible error, that i'm unable to solve:

RMAN> list failure;

Database Role: PHYSICAL STANDBY

List of Database Failures

=========================

Failure ID Priority Status Time Detected Summary

---------- -------- --------- ------------------- -------

8087 HIGH OPEN 2017-02-09 17:45:09 Datafiles are mutually inconsistent

RMAN> advise failure;

Database Role: PHYSICAL STANDBY

List of Database Failures

=========================

Failure ID Priority Status Time Detected Summary

---------- -------- --------- ------------------- -------

8087 HIGH OPEN 2017-02-09 17:45:09 Datafiles are mutually inconsistent

Mandatory Manual Actions

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1. Ensure the primary database is up and recover database using ALTER DATABASE RECOVER MANAGED STANDBY DATABASE UNTIL CONSISTENT command. Check alert log for potential failures that may cause recovery not to run. Potential problems may include missing archived logs or datafiles being in an orphaned incarnation.

2. Contact Oracle Support Services if the preceding recommendations cannot be used, or if they do not fix the failures selected for repair

Optional Manual Actions

=======================

no manual actions available

Automated Repair Options

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no automatic repair options available

I have checked the alert log and haven't found anything from there. I have done the "ALTER DATABASE RECOVER MANAGED STANDBY DATABASE UNTIL CONSISTENT" and it's still present.

The backup scheduled job runs on standby only and is stored locally. Just in case, i'll paste the scripts:
backup job:

backup device type disk tag '%TAG' database;

backup device type disk tag '%TAG' archivelog all not backed up;

allocate channel for maintenance type disk;

delete noprompt obsolete device type disk;

release channel;

cleanup script:

resync catalog;

CROSSCHECK BACKUP;

DELETE NOPROMPT EXPIRED BACKUP;

delete noprompt obsolete device type disk;

CROSSCHECK  ARCHIVELOG ALL;

delete noprompt archivelog until time "SYSDATE-2";

list backup summary;

list backup of controlfile;

list backup of spfile;

list backupset;

list archivelog all;

validate spfile;

report need backup;

RESTORE DATABASE VALIDATE;

restore archivelog from time 'sysdate-1' validate;

RESTORE CONTROLFILE VALIDATE;

list failure;

advise failure;

I have checked the scn numbers and they match.

Some time ago that same problem has been up on production env aswell.

In case the tags are not enouth:

we run 12c, dataguard with physical standby on OEL latest.

Has anybody been faced with this?