How to kill "controlfile autobackup" operation that is causing ORA-00230

Hello,

The database and O.S. configuration is:

Oracle 11.2.0.4 2-node RAC on Red Hat Enterprise Linux Server release 5.11

RMAN backup fails with the following:

Starting Control File and SPFILE Autobackup at 13-MAR-19RMAN-00571: ===========================================================RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============RMAN-00571: ===========================================================RMAN-03009: failure of Control File and SPFILE Autobackup command on ORA_DISK_1 channel at 03/14/2019 00:11:15ORA-00230: operation disallowed: snapshot control file enqueue unavailable

I followed the MOS document:

RMAN: Backup Fails with ORA-230 Snapshot Controlfile Enqueue Unavailable (Doc ID 145619.1)

Performed the following (modified) SQL for RAC:

SELECT s.inst_id, s.sid, username AS "User", program, module, action, logon_time "Logon", l.*  FROM gv$session s, gv$enqueue_lock lWHERE s.inst_id=l.inst_id and l.sid = s.sid and l.type = 'CF' AND l.id1 = 0 and l.id2 = 2;