Shutdown immediate stays there

Today, I used PL/SQL to connect to the server without any response. I can log on to the server and connect to sqlplus directly. Then I found that the lsnrctl status is always connect.
 
Try shutdown immediate and stop there. You can only use shutdown abort to force shutdown.
 
After the lsnrctl status is disabled, the connection is still found. Use ps-ef | grep tns to locate the listening process and kill it.
 
Now the client can log on

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