SYS password has expired and cannot be changed due to ORA-00257: Archiver error

Oracle 18c

In the past : When I had once the error ORA-00257: Archiver error, I had resolved it using the RMAN command:

rman target sys/1234

delete archivelog all;

This time , when I try to connect to rman target:

rman target sys/1234

I get the error:

RMAN-00554: initialization of internal recovery manager packagefailed.  
RMAN-04005: error from target database.  
ORA-28001:the password has expired.

When I try to connect with sqlplus as sys SYSDBA, then raises the following error: ERROR:

ORA-28001: the password has expired
Changing password for SYS
New password:

When I type the new password, the error that comes is: