bpbackup doesn't write file log with -w option

Hello,

I have a bpbackup process running ok, but when I add to the same command the option -w It doesn't write in the file log. The command is the following:

/usr/openv/netbackup/bin/bpbackup -w -c SFE_UNIX_TRIMESTRAL -s USER_DIARIO -S mrbackup -t 0 -L /opt/logs/Backup_log.txt /backup

I try also with the following command but the result is the same:

/usr/openv/netbackup/bin/bpbackup -w -c SFE_UNIX_TRIMESTRAL -s USER_DIARIO -S mrbackup -t 0 /backup >/opt/logs/Backup_log.txt

Thanks.